MATLAB: How to reduce dimension of griddedinterpolant

girdded dataMATLAB

I have a gridded efficiency map where each point depends on different input values for current and voltage.
F = griddedInterpolant(x_voltage,y_current,eff_map)
% and query points
eff = F(voltage_set,current_set)
Now I want to convert this map while runtime of a program to a curve for a fixed voltage, so that the efficiency just depends on the current/power.
Kind of,
function new_F = reduceDimension(F,fixed_voltage)
...
end
eff = new_F(power_set)
I can't find a quick solution, maby someone has an idea.
THX

Best Answer

  • whos
    Name Size Bytes Class Attributes
    eff_map 500x500 2000000 double
    x_voltage 500x500 2000000 double
    y_current 500x500 2000000 double
    We are given some data as arrays, and you understand how to use griddedInterpolant. What you need to learn next is about building a function handle.
    F = griddedInterpolant(x_voltage,y_current,eff_map)
    Now, you want to reduce that, for a FIXED voltage, to a function of only one variable. Since 42 is the answer to everything, I'll fix the voltage at 42.
    FixedVolts = 42;
    F_v42 = @(y) F(repmat(FixedVolts,size(y)),y);
    That is all it takes. We can now evaluate the new function at some value or a list of values for the current. We can even plot it as a function of one variable now. I've even set up F_42v in such a way that we can even pass in a complete vector or array for y. The result will be the same shape and size as the input for y.
    F_v42(17)
    ans =
    0.881963765526607
    F_v42([1 3 5])
    ans =
    0.0952082740655224 0.230322190630928 0.381508409480828
    fplot(F_v42,[0,50])
    xlabel 'y_current'
    ylabel 'eff_map @ x = 42'