kml_float_spline_eval_deriv

这个函数返回插值函数对于给定点(x)的微分。计算中使用插值对象interp，数据数组xarr，yarr以及加速器xacc。对于x在xarr的区间外，将返回报错信息。

接口定义

int kml_float_spline_eval_deriv_e(const kml_float_spline *spline, float x, kml_spline_accel *a, float *dydx)

float kml_float_spline_eval_deriv(const kml_float_spline *spline, float x, kml_spline_accel *a)

参数

参数名	类型	描述	输入/输出
spline	kml_float_spline*	插值对象指针	输入
x	float	求解点x的值	输入
y	float	求解点y的值	输入
a	kml_spline_accel *	加速器对象指针	输入

依赖

#include "kml_spline.h"

示例

const size_t xMin = 4;
const size_t xMax = 2048;
const size_t xSize = 4;
const float xValLo = 1;
const float xValHi = 2;
float xArr[4] = {1,1.33,1.67,2};
float* yArr = (float*)malloc(xSize * sizeof(float));
float x = 1;
float y = 0;
kml_float_spline *spline = kml_float_spline_alloc(kml_float_interp_cspline, xSize);
kml_interp_accel *xacc = kml_interp_accel_alloc();
kml_float_spline_init(spline, xSize, xArr, yArr);
y = kml_float_spline_eval_deriv(spline, xArr, x, xacc);
kml_float_spline_free(spline);
kml_interp_accel_free(xacc);
free_if_not_null(xArr);

父主题： spline