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Hello everyone
i want to define a feedforward controller by InterpolataryCubicSpline function
my control points are: x=[0 0.3 0.5 0.75 1] y=[0 -10 0 10 0]
and my code is:
ConditionalController{
states = "EarlyStance LateStance Liftoff Swing Landing"
FeedForwardController{
include = hip_flexion*
InterpolataryCubicSpline{
control_points = 5
control_point_y = {Y0=0 Y1=-10 Y2=0 Y3=10 Y4=0}
control_point_dt = {T0=0 T1=0.3 T2=0.2 T3=0.25 T4=0.25}
cyclic = 1
}
}
}

but i got this error:
GaitStateController:
FeedForwardController:
Could not find key: mean or init_mean

and another question is how should i define tangent_begin_type? i tried to use it like tangent_begin_type="0" but that was not correct

You cannot initialize the individual control point parameters from within this function. If you want different initial values for each control point, you can do so via a "Parameters" section inside the SimulationObjective, or via a custom .par init_file inside the CmaOptimizer.

Thank you so much, it worked very well.
but i still have problem with defining control_point_tangent and tangent_begin_type
could you please give an example to show how to put values for these two Parameters? (e.g. for 5 control points)

In continuation of the previous post, i defined the function like this:
InterpolataryCubicSpline{
control_points = 8
control_point_y = ~10
control_point_dt = ~0.2
control_point_tangent = {0 0 0 0 0 0 0 0}
flat_extrapolation = 1
cyclic = 1
}
and i got this error:
Error parsing line 162: Expected '=', ':', '{' or '['
i tried all the possible forms for putting the values of control_point_tangent but it didn't work.
is this Parameter working?!

To be honest, I'm not sure how the InterpolataryCubicSpline works exactly, as it was a contribution from another developer (Alex Zhou). I've emailed him with a request to look at your issue.

I found a few old test cases scattered around, here are a few examples that may get you started.
I did not retest these functions but you can try or modify some of them for your purposes.

FeedForwardController {
name = ctrl1
symmetric = 1

InterpolataryCubicSpline {
spline_type = CatmullRomSpline
tangent_begin_type = Zero
tangent_end_type = Zero
zero_start = 1
zero_end = 1
#cyclic = 1
#offset_time = 0.0~0.02<-0.1,0.1>
#scale_time = 1.4~0.1<1.2,1.6>
control_points = 3

#control_point_y = 0.5~0.2<0,1> # Initial y value of control points
control_point_dt = 0.3~0.05<0.2,0.4> # initial delta time between control points
coefficient0 = -0.5#~0.2<-0.5,0> #extension
coefficient1 = 0.0
coefficient2 = 0.5#~0.02<0,0.5>, #flexion
#delta_time0 = 0.05~0.005<0.01,0.1>
}
}

FeedForwardController {
name = ctrl2
symmetric = 1

InterpolataryCubicSpline {
spline_type = CubicHermiteSpline
cyclic = 1
offset_time = 0.1~0.025<0.05,0.2>
#scale_time = 1.4~0.1<1.2,1.6>
control_points = 4

#control_point_y = 0.5~0.2<0,1> # Initial y value of control points
control_point_dt = 0.25~0.05<0.2,0.4> # initial delta time between control points
delta_time2 = 0.7~0.2<0.5,1.0>

coefficient0 = 0.0
coefficient1 = -0.5~0.1<-1.0,0> #extension
coefficient2 = 0.0
coefficient3 = 0.0

tangent0 = 0.0
tangent1 = 0.0
tangent2 = 0.0
tangent3 = 0.0

}
}


FeedForwardController {
name = ctr3
symmetric = 1

InterpolataryCubicSpline {
spline_type = NatCubSpline
zero_start = 1
zero_end = 1
#flat_extrapolation = 1 #zero_end will auto set to flat_extrapolation true
control_points = 5
#control_point_y = 0.5~0.2<0,1> # Initial y value of control points
control_point_dt = 0.125~0.02<0.01,1> # initial delta time between control points
coefficient0 = -0.5~0.2<-1,0>
coefficient1 = -0.1~0.02<-1,0>
coefficient2 = 0.0
coefficient3 = 0.1~0.02<0,1>
coefficient4 = 0.5~0.2<0,1>
delta_time0 = 0.05~0.005<0.01,0.1>
}
}

Thanks a lot
it helped me so much.