Spline library, errors compiling example code

Projects Programming
1

Hi All,

I tried adding the spline library GitHub - kerinin/arduino-splines: 1D splines for the arduino environment to my project and it doesn't want to compile.
The first error I got was undefined ref to WProgram.h, which I changed to Arduino.h in the cpp and h files.

I am just trying to compile the example pde

#include <spline.h>

Spline tempCurve;

void setup(void) {
  Serial.begin(9600);
  
  double x[7] = {-1,0,1,2,3,4, 5};
  double y[7] = { 0,0,8,5,2,10,10};
  tempCurve.setPoints(x,y,7);
  tempCurve.setDegree( Catmull );
  
  for( float i = 0; i <= 4; i+= .1 ) {
    float temp = tempCurve.value(i);
    Serial.print(i);
    for(float j=0; j<= temp; j += .2) {
      Serial.print( "*" );
    }
    Serial.print( "   " );
    Serial.println(temp);
  }
}

void loop(void) {

}

But now I try to compile and get: "no matching function for call to Spline..."

sketch_mar31a.cpp: In function 'void setup()':
sketch_mar31a:9: error: no matching function for call to 'Spline::setPoints(double [7], double [7], int)'
C:\Users\Public\Documents\arduino-1.0\libraries\spline/spline.h:21: note: candidates are: void Spline::setPoints(float*, float*, int)
C:\Users\Public\Documents\arduino-1.0\libraries\spline/spline.h:22: note: void Spline::setPoints(float*, float*, float*, int)

What can I do to get this library working?

Thanks in advance!

2

There is no function which takes double arrays - you have to use float arrays

3 
double x[7] = {-1,0,1,2,3,4, 5};
  double y[7] = { 0,0,8,5,2,10,10};
  tempCurve.setPoints(x,y,7);

the example uses doubles for the x and y arrays, but the library wants float, see error output: "note: candidates are: void Spline::setPoints(float*, float*, int)"

try

float x[7] = {-1,0,1,2,3,4, 5};
  float y[7] = { 0,0,8,5,2,10,10};
4

It should be noted that floats and doubles, on the Arduino, are the same size, so no loss of precision will occur using floats instead of doubles.

5

THANKS!

Arduino error readouts are usually pretty intimidating :slight_smile: