Arrays have incompatible sizes for this operation

Hey guys, thanks in advance.

Im trying to apply this equation on matlab

However i Keep getting this error , arrays have incompatible sizes for this operation, I dont understand since there are only constants and when there is a vector I do this .*

This is the code:

D is not getting any error, only H_BAC.

I ve attached the data

n=1;
u=2;
Lp=1;
fc=30e6;
c=3e8;
Vr=250;

D=sqrt(1-((u.^2*doppler_freqSurv.^2*c.^2)/4*Vr.^2*fc.^2));
H_BAC=exp(1*j*2*pi*((R1_matrix-Rm_matrix+n*Lp)/c*fc .*D));

Answer 1

[Voss]

R1_matrix and Rm_matrix are 1x400:

load R1_matrix
load Rm_matrix
whos R*

  Name           Size             Bytes  Class     Attributes

  R1_matrix      1x400             3200  double              
  Rm_matrix      1x400             3200  double              

Therefore, the expression involving subtracting Rm_matrix from R1_matrix gives a 1x400 vector (here stored as the variable temp):

n=1;
u=2;
Lp=1;
fc=30e6;
c=3e8;
Vr=250;
temp = (R1_matrix-Rm_matrix+n*Lp)/c*fc;
whos temp

  Name      Size             Bytes  Class     Attributes

  temp      1x400             3200  double              

The result of that expression should be multiplied element-wise by D, but D is 1x8000:

load D
whos D

  Name      Size               Bytes  Class     Attributes

  D         1x8000            128000  double    complex   

So you can't do it:

H_BAC=exp(1*j*2*pi*(temp.*D));

Arrays have incompatible sizes for this operation.

Hard to say what the right thing to do is with the information given.

[Miguel Albuquerque]

If i put zeros in R1 and Rm in order to fill to 1 x 8000?

[Dyuman Joshi]

Then you will be able to do that operation.

[Miguel Albuquerque]

Is there fast way to do that?

[Dyuman Joshi]

R1_matrix=[zeros(1,size(D,1)-size(R1_matrix,1)) R1_matrix] %padding ahead

[Miguel Albuquerque]

that is giving me a R1 of 1x 400 , it doesnt change anything

[Dyuman Joshi]

That was to be done after defining D.

Change D to doppler_freqSurv and try again

[Miguel Albuquerque]

n=1;
u=2;
D=sqrt(1-((u.^2*doppler_freqSurv.^2*c.^2)/4*Vr.^2*fc.^2));
R1_matrix=[zeros(1,size(doppler_freqSurv,1)-size(R1_matrix,1)) R1_matrix] %padding ahead

This is not changing anything in R1

[Miguel Albuquerque]

Here it is the best way, thanks anyways

R1_matrix(numel(D))=0;