initial
This commit is contained in:
399
c/splines/linear/linear_splines.c
Normal file
399
c/splines/linear/linear_splines.c
Normal file
@@ -0,0 +1,399 @@
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#define interpol_splines_linear_c
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#include "linear_splines.h"
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#include "../../internal_deque.h"
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double linear_spline_eval_double(
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double x
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, interpol_splines_linear_InterPolator * interpolator)
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{
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unsigned long int i = 0;
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double * X = PyArray_DATA(interpolator->x);
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double * Y = PyArray_DATA(interpolator->y);
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// Outside the known data.
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if(x < X[0])
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{
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return 0;
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}
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// Somehow this has to be handled explicitly.
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if(x == X[0])
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{
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i = 1;
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}
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else
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{
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while(x < X[i] && i < interpolator->grid_points)
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{
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i++;
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}
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}
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return Y[i - 1] + (x - X[i - 1]) / (X[i] - X[i - 1]) * (Y[i] - Y[i - 1]);
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}
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float linear_spline_eval_float(
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float x
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, interpol_splines_linear_InterPolator * interpolator)
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{
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unsigned long int i = 0;
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float * X = PyArray_DATA(interpolator->x);
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float * Y = PyArray_DATA(interpolator->y);
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// Outside the known data.
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if(x < X[0])
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{
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return 0;
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}
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// Somehow this has to be handled explicitly.
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if(x == X[0])
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{
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i = 1;
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}
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else
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{
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while(x < X[i] && i < interpolator->grid_points)
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{
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i++;
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}
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}
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return Y[i - 1] + (x - X[i - 1]) / (X[i] - X[i - 1]) * (Y[i] - Y[i - 1]);
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}
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static PyObject *
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interpol_splines_linear_InterPolator_new
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( PyTypeObject * type
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, PyObject * args
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, PyObject * kwds)
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{
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interpol_splines_linear_InterPolator * self = (interpol_splines_linear_InterPolator *) type->tp_alloc(type, 0);
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return (PyObject *) self;
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}
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static int
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interpol_splines_linear_InterPolator_init
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( interpol_splines_linear_InterPolator * self
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, PyObject * args)
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{
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if(!PyArg_ParseTuple(args, "O!O!"
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, &PyArray_Type, &(self->x)
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, &PyArray_Type, &(self->y)))
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{
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return -1;
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}
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// Check for proper data types & dimensions first.
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if(self->x->nd != 1)
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{
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PyErr_SetString(PyExc_ValueError, "x has to have 1 dimension");
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return -1;
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}
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if(self->y->nd != 1)
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{
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PyErr_SetString(PyExc_ValueError, "y has to have 1 dimension");
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return -1;
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}
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if(PyArray_TYPE(self->x) != PyArray_TYPE(self->y))
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{
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PyErr_SetString(PyExc_TypeError, "x and y have to have the same data type");
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return -1;
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}
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if(PyArray_TYPE(self->x) == NPY_FLOAT)
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{
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self->eval = linear_spline_eval_double;
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}
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else if(PyArray_TYPE(self->x) == NPY_DOUBLE)
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{
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self->eval = linear_spline_eval_float;
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}
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else
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{
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PyErr_SetString(PyExc_TypeError, "x and y have to be either float or double");
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return -1;
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}
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if(self->x->dimensions[0] != self->y->dimensions[0])
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{
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PyErr_SetString(PyExc_ValueError, "x and y must have the same length");
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return -1;
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}
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if((PyArray_FLAGS(self->x) & NPY_CARRAY_RO) != NPY_CARRAY_RO)
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{
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PyErr_SetString(PyExc_ValueError, "x must be a readable C Array");
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return -1;
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}
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if((PyArray_FLAGS(self->y) & NPY_CARRAY_RO) != NPY_CARRAY_RO)
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{
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PyErr_SetString(PyExc_ValueError, "y must be a readable C Array");
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return -1;
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}
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self->grid_points = self->x->dimensions[0];
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Py_INCREF(self->x);
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Py_INCREF(self->y);
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return 0;
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}
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static PyObject *
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interpol_splines_linear_InterPolator_eval_pyfloat
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( interpol_splines_linear_InterPolator * self
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, PyObject * args
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)
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{
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double x;
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double result;
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if(!PyArg_ParseTuple(args, "d", &x))
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{
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return NULL;
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}
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result = (double) (self->eval)(x, self);
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return Py_BuildValue("d", result);
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}
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PyDoc_STRVAR(interpol_splines_linear_InterPolator_eval_pyfloat_doc
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, "evaluate the spline at the given point");
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/*
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static PyObject *
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interpol_splines_linear_InterPolator_eval_ndarray
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( interpol_splines_linear_InterPolator * self
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, PyObject * args
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)
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{
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PyArray * x;
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PyArray * y;
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if(!PyArg_ParseTuple(args, "O!O!", &PyArray_Type, &x, &PyArray_Type, &y))
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{
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return NULL;
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}
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if(PyArray_FLAGS(x) & NPY_CARRAY_RO != NPY_CARRAY_RO)
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{
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PyErr_SetString(PyExc_ValueError, "x must be a readable c array");
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return NULL;
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}
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if(PyArray_FLAGS(y) & NPY_CARRAY_RW != NPY_CARRAY_RW)
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{
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PyErr_SetString(PyExc_ValueError, "y must be a readable and writable c array");
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return NULL;
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}
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if(PyArray_TYPE(x) != NPY_FLOAT
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&& PyArray_TYPE(x) != NPY_DOUBLE)
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{
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PyErr_SetString(PyExc_TypeError, "x must be either float or double");
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return NULL;
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}
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if(PyArray_TYPE(x) != PyArray_TYPE(y))
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{
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PyErr_SetString(PyExc_TypeError, "x and y must have same datatype");
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return NULL;
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}
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if(PyArray_Size(x) != PyArray_Size(y))
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{
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PyErr_SetString(PyExc_ValueError, "x and y must have same length");
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}
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npy_intp size = PyArray_NBYTES(x);
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npy_intp element_size = PyArray_ITEMSIZE(x);
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char * x_data = PyArray_BYTES(x);
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char * y_data = PyArray_BYTES(y);
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// FIXME:
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// I have to pay attention to datatypes here.
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while(x_data < size)
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{
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*y_data = self->eval(*x, self);
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}
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}
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*/
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int
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interpol_splines_linear_InterPolator_equals_pyfloat_search_float
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( interpol_splines_linear_InterPolator * self
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, i_deque_t ** deque
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, double y)
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{
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float * x_data = (float *) PyArray_DATA(self->x),
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* y_data = (float *) PyArray_DATA(self->y);
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PyObject * this_result;
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long unsigned int i;
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for(i = 1; i < self->grid_points; i++)
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{
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if(y_data[i - 1] <= y && y_data[i] >= y)
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{
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// just avoid zero division
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if(y_data[i - 1] == y_data[i])
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{
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this_result = PyFloat_FromDouble(x_data[i - 1]);
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if(!this_result)
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{
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return -1;
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}
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*deque = i_deque_t_insert(*deque, this_result);
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continue;
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}
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this_result = PyFloat_FromDouble(
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(y - y_data[i - 1]) / (y_data[i] - y_data[i - 1]) * (x_data[i] - x_data[i - 1]) + x_data[i - 1]);
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if(!this_result)
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{
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return -1;
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}
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*deque = i_deque_t_insert(*deque, this_result);
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}
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}
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return 0;
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}
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int
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interpol_splines_linear_InterPolator_equals_pyfloat_search_double
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( interpol_splines_linear_InterPolator * self
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, i_deque_t ** deque
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, double y)
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{
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double * x_data = (double *) PyArray_DATA(self->x),
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* y_data = (double *) PyArray_DATA(self->y);
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PyObject * this_result;
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long unsigned int i;
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for(i = 1; i < self->grid_points; i++)
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{
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if(y_data[i - 1] <= y && y_data[i] >= y)
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{
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// just avoid zero division
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if(y_data[i - 1] == y_data[i])
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{
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this_result = PyFloat_FromDouble(x_data[i - 1]);
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if(!this_result)
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{
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return -1;
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}
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*deque = i_deque_t_insert(*deque, this_result);
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continue;
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}
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this_result = PyFloat_FromDouble(
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(y - y_data[i - 1]) / (y_data[i] - y_data[i - 1]) * (x_data[i] - x_data[i - 1]) + x_data[i - 1]);
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if(!this_result)
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{
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return -1;
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}
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*deque = i_deque_t_insert(*deque, this_result);
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}
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}
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return 0;
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}
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static PyObject *
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interpol_splines_linear_InterPolator_equals_pyfloat
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( interpol_splines_linear_InterPolator * self
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, PyObject * args)
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{
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double y;
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if(!PyArg_ParseTuple(args, "d", &y))
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{
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return NULL;
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}
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i_deque_t * deque = i_deque_t_start();
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if(PyArray_TYPE(self->y) == NPY_FLOAT)
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{
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interpol_splines_linear_InterPolator_equals_pyfloat_search_float(self, &deque, y);
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}
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else
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{
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interpol_splines_linear_InterPolator_equals_pyfloat_search_double(self, &deque, y);
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}
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return i_deque_t_to_List(deque);
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}
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PyDoc_STRVAR(interpol_splines_linear_InterPolator_equals_pyfloat_doc
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, "return a deque to all the points where s(x) = y");
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static PyMethodDef interpol_splines_linear_InterPolator_Methods[] =
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{
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{"eval_float", (PyCFunction) interpol_splines_linear_InterPolator_eval_pyfloat, METH_O, interpol_splines_linear_InterPolator_eval_pyfloat_doc}
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, {"equals_float", (PyCFunction) interpol_splines_linear_InterPolator_equals_pyfloat, METH_O, interpol_splines_linear_InterPolator_equals_pyfloat_doc}
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, {NULL, NULL, 0, NULL}
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};
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static PyTypeObject interpol_splines_linear_InterPolatorType =
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{
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PyVarObject_HEAD_INIT(NULL, 0)
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"interpol.splines.linear.do.Interpolator",
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sizeof(interpol_splines_linear_InterPolator),
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0, /* tp_itemsize */
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0, /* tp_dealloc */
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0, /* tp_print */
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0, /* tp_getattr */
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0, /* tp_setattr */
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0, /* tp_reserved */
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0, /* tp_repr */
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0, /* tp_as_number */
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0, /* tp_as_sequence */
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0, /* tp_as_mapping */
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0, /* tp_hash */
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0, /* tp_call */
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0, /* tp_str */
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0, /* tp_getattro */
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0, /* tp_setattro */
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0, /* tp_as_buffer */
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Py_TPFLAGS_DEFAULT ,/* tp_flags */
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"The backend for linear splines.",
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0,
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0,
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0,
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0,
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0,
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0,
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interpol_splines_linear_InterPolator_Methods, // methods
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0, // members
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0,
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0,
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0,
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0,
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0,
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0,
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(initproc) interpol_splines_linear_InterPolator_init,
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0,
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interpol_splines_linear_InterPolator_new,
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};
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static PyModuleDef interpol_splines_linear_do_module =
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{
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PyModuleDef_HEAD_INIT,
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"interpol.splines.linear.do",
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"module containing the backend to linear splines",
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-1,
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NULL,NULL,NULL,NULL,NULL
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};
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PyMODINIT_FUNC PyInit_do(void)
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{
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PyObject * module;
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if(PyType_Ready(&interpol_splines_linear_InterPolatorType) < 0)
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{
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return NULL;
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}
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module = PyModule_Create(&interpol_splines_linear_do_module);
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if(!module)
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{
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return NULL;
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}
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Py_INCREF(&interpol_splines_linear_InterPolatorType);
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PyModule_AddObject(module, "InterPolator", (PyObject *) &interpol_splines_linear_InterPolatorType);
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import_array();
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return module;
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}
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35
c/splines/linear/linear_splines.h
Normal file
35
c/splines/linear/linear_splines.h
Normal file
@@ -0,0 +1,35 @@
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#ifndef interpol_splines_linear_h
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#define interpol_splines_linear_h
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#include <Python.h>
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#include <numpy/arrayobject.h>
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typedef struct _interpol_splines_linear_InterPolator_s
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{
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PyObject_HEAD
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long unsigned int grid_points;
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PyArrayObject * x;
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PyArrayObject * y;
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// This is either
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// linear_spline_eval_double or linear_spline_eval_float and
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// is used to evaluate the spline at a given x efficiently.
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double (* eval)(double, struct _interpol_splines_linear_InterPolator_s *);
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} interpol_splines_linear_InterPolator;
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double linear_spline_eval_double
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( double x
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, interpol_splines_linear_InterPolator * interpolator
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);
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float linear_spline_eval_float
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( float x
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, interpol_splines_linear_InterPolator * interpolator
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);
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#ifndef interpol_splines_linear_c
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#endif
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#endif
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Reference in New Issue
Block a user