Error using plot Vectors must be the same length.

Hello,

I am trying to plot Radius verses temperature in my code. Radius is matrix (2030x1354 double) and I just want to plot the radius where M_CP = 2 therefore I did indexing and result is a column vector 668557x1. I've searched that error is because of the different dimensions of x and y but I am unable to resolve this issue. Kindly suggest me what should I do to plot it correctly. Thank you.

M_CP = double(Data_CP); % 2030 x 1354 double (it has values 1, 2, 3 and 4)
M_CT = double(Data_CT); % 2030 x 1354 double
M_CRAD=double(Data_CRAD);   
 Radius = (M_CRAD).* 0.01;  % 2030x1354 double            
 
 cldTT = (M_CT -(-15000)).* 0.01; % Converting from Kelvin to C
 cldTT1 = cldTT- 273.15; % 2030x1354 double

 index_liq = M_CP == 2; %index to find where M_CP ==2
 M_RAD_LIQ = Radius(index_liq); % 668557x1 double 
 
 plot(M_RAD_LIQ,cldTT1)
 
 Error using plot
Vectors must be the same length.

Answer 1

[dpb]

On the right track, just have to use the index for both variables...

 index_liq = (M_CP==2);                         % index to find where M_CP ==2
 plot(Radius(index_liq),cldTT1(index_liq))      % plot matching records

NB: You don't need the temporary variable to plot; it may well be convenient to create it for later use if doing a lot with it, but doing so instead of just using the logical addressing vector does create a copy in memory of the same data as already have (and the temperature variable along with it or any other variables of same condition). Since this is a pretty-decent-sized variable, that could have ramifications if done indiscriminantly.

[IMC]

Unfortunately, I didn't get the line plot. This is the figure I got after using above lines of code:

[dpb]

Well, your data aren't in order, then, but with radii of given magnitudes all jumbled up in sequence...

Either use scatter() instead or plot() without a solid line or

 index_liq = (M_CP==2);                         % index to find where M_CP ==2
 [~,ixOrder]=sort(Radius(index_liq));           % get the sorted order of radius values
 plot(Radius(index_liq(ixOrder)),cldTT1(index_liq(ixOrder)))      % plot matching records in sorted order