MATLAB: How to get the corresponding data from a table

contourspeed

I am trying to get the corresponding efficiency number from this efficiency map. I have list of speed and torque for which i need the corresponding efficiency number.
This is the code for efficiency calculation: 
tr =[0:1:Trrated]; % list of torque values in increments of 1Nm
Nr =[0:100:Nrmax]; % specifies range of speed values in increment 100rpm
[X,Y] = meshgrid(Nr,tr); % defines x and y axis of torque-speed plot
Pr = X*pi/30.*Y; % Calculating the motor output or rotor power based on P=Tw
Pr(Pr>Prrated) = 0; % limiting power to 80kW
Iphd = -Iphm*(1-Nrrated./X); % field-weakening current above rated speed
Iphd(Nr>Nrrated) = 0; % and zero below rated speed 
Pin = Pr+3*Rs*((Y./k/3).^2)+(Tnl.*X.*(pi/30))+3*Rs*((Iphd).^2); % motor input power
Eff = Pr./Pin; % efficiency map based on the torque-speed ranges given
Tlim = Prrated./(Nr.*(pi/30)); % setting a torque limited curve based on max power and speed
Tlim(Tlim>Trrated) = Trrated; % max torque value set
[C,h] = contourf(X,Y,Eff,[0.7 0.85 0.9 0.92, 0.94, 0.96],'k'); % prepare for contour lines and spacing
clabel(C,h,'manual') ; % this displays the contour values
l = colorbar; % adds a colorbar to the right of the plot
From this i need to find the corresponding efficiency number for my speed and torque. Appreciate any help.
Thank you!

Best Answer

If the efficiency number is an individual entry stored in the efficiency map, then:
eff_number = interp2(X, Y, Eff, speed_of_interest, torque_of_interest)
Related Question