akimasplineΒΆ

akimaspline computes an akima spline for a given x- and y-vector.

rmXY = akimaspline(rvX, rvY, p, flag)

Return Value

The return value rmXY is a real matrix with two columns. The first column contains the x-coordinates of the spline and the second column contains the y-coordinates of the spline. In case of an error rmXY has only one element with an error number:

1 not enough memory
2 x-coordinates are not strictly increasing
3 less than 3 datapoints specified.

Parameters

rvX

rvX is a real vector with at least 3 elements in increasing order. The values must be strictly increasing.

rvY

rvY is a real vector with at least 3 elememts.

p

The meaning of p depends on the value of the parameter flag

flag

flag can be one of the following values:

Value Meaning
1 p is the number of x-, y-coordinates calculated.
2 p is the number of x-, y-coordinates calculated. The original x-coordinates are added to the total.
3 p is a strictly increasing vector of x-coordinates.

Example

../../_images/akimaspline.png
x = [1,3,5,8]
y = [0,5,8,2]
h = plot(x,y)
xy = akimaspline(x,y,50,2)
plot(xy[;1],xy[;2],h[2])
xy = fspline(x,y,0,50)
plot(xy[;1],xy[;2],h[2])

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