Why does it say "Subscripted assignment dimension mismatch" ? possibly because of NaN's?

Question

Michael 2014-8-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/146235-why-does-it-say-subscripted-assignment-dimension-mismatch-possibly-because-of-nan-s

编辑： Geoff Hayes 2014-8-6

I am interpolating triscattered data onto a regular grid. It works but then stops at t = 10, I don't know why it is doing this!.. I think i had this problem a while back and I managed to sort it but I can't seem to fix it this time. Does anyone know what is wrong? see after code for data dimensions...

weight = cos(REF_lat);

[x,y]=meshgrid(0:1:360,-66:1:66);
x=x(1:end-1,1:end-1); y=y(1:end-1,1:end-1);
load('/work/uo0122/u253082/Mat_Time_Subsampled/STORM_10d_TJJ_ssh_orig_sampling.mat');
s = STORM_10d_TJJ_ssh_orig_sampling;
mask = zeros(size(depth)); 
mask(find(depth > 0)) = 1;
AM = ones(663,132,360);
Wrep = ones(663,132,360);
for t = 1:size(s,1);
    t
    tic
    a=squeeze(s(t,:,:));
      a=a(:);
      bad1=find(isnan(a)==1);
      a(bad1)=[];
      lon=REF_lon(:);
      lon(bad1)=[];
      lat=REF_lat(:);
      lat(bad1)=[]; 
      w = weight(:);
      w(bad1)=[];
      F1=TriScatteredInterp(lon,lat,a,'natural');
      W1=TriScatteredInterp(lon,lat,w,'natural');
      a_m=F1(x,y);
      AM(t,:,:)=a_m;
      W=W1(x,y);
      Wrep(t,:,:)=W;
      toc
end

weight = 3127 x 254 s = 663 x 3127 x 254 * you can ignore mask

The data I get afterwards looks reasonable too. My biggest suspicion is that it is because it is a timestep that is just NaN's, I tried removing the NaN's but I couldn't seem to do it properly.

Thanks in advance! Michael

8 个评论
显示 6更早的评论隐藏 6更早的评论

Geoff Hayes 2014-8-5

在 MATLAB Online 中打开

Michael - which line of code is throws the error? Since it is failing only at t equal to 10, then why not step through the code with the debugger?

Either put a breakpoint at the line that throws the error, run the code, and hit continue until you get to the tenth iteration. Or, prior to running the function (or script), run the following command in the Command Window

dbstop if error

Now as you run your function (or script), when an error is encountered the debugger will jump to the line in the function that threw the error.

You can now examine each variable on the left- and right-hand side of the assignment and determine why the subscripted assignment dimension mismatch error is thrown.

An example of this type of error is when an assignment of too little or too much data is being made. For example, suppose we do the following

 % create a 4x4 matrix of ones
 Z=ones(4,4);
 % assign a 1x4 vector to a 1x2 space within the matrix
 Z(2,1:2) = ones(1,4);

The above is impossible, and the

Subscripted assignment dimension mismatch.

error is thrown.

Michael 2014-8-6

thanks, Geoff!

Geoff Hayes 2014-8-6

No problem, Michael!

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Geoff Hayes 2014-8-6

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/146235-why-does-it-say-subscripted-assignment-dimension-mismatch-possibly-because-of-nan-s#answer_147575

在 MATLAB Online 中打开

For the case of t being equal to ten, it was found that the line of code that was generating the Subscripted assignment dimension mismatch error was

a_m=F1(x,y);

The variables F1, lon, lat, and weight were all empty due to the all elements in the s(t,:,:) matrix being set to NaN.

A solution was to address this in the code as follows - if it was found that the a matrix was empty (after the removal of NaNs) then do nothing (or set the output to be all zeros) and just continue with the next iteration of the for loop

 a=squeeze(s(t,:,:));
 a=a(:);
 bad1=find(isnan(a)==1);
 a(bad1) = [];
 if isempty(a)
      % maybe set all AM data to zero for this t
      AM(t,:,:) = 0;
 else
      lon=REF_lon(:);
      lon(bad1)=[];
      lat=REF_lat(:);
      lat(bad1)=[]; 
      w = weight(:);
      w(bad1)=[];
      F1=TriScatteredInterp(lon,lat,a,'natural');
      W1=TriScatteredInterp(lon,lat,w,'natural');
      a_m=F1(x,y);
      AM(t,:,:)=a_m;
      W=W1(x,y);
      Wrep(t,:,:)=W;
 end

2 个评论
显示无隐藏无

Michael 2014-8-6

在 MATLAB Online 中打开

thanks, I ended up using this command in the world, but in a musch simpler way within the loop:

    if isempty(a_m) == 0;
        AM(t,:,:)=a_m;
    end

Geoff Hayes 2014-8-6

编辑：Geoff Hayes 2014-8-6

在 MATLAB Online 中打开

Good that you have it working. Am just unsure of one thing: I thought that the error was being generated from the previous line

a_m=F1(x,y);

请先登录，再进行评论。

Why does it say "Subscripted assignment dimension mismatch" ? possibly because of NaN's?

8 个评论
显示 6更早的评论隐藏 6更早的评论

采纳的回答

2 个评论
显示无隐藏无

更多回答（0 个）

另请参阅

类别

标签

产品

Community Treasure Hunt

Why does it say "Subscripted assignment dimension mismatch" ? possibly because of NaN's?

8 个评论 显示 6更早的评论隐藏 6更早的评论

采纳的回答

2 个评论 显示 无隐藏 无

更多回答（0 个）

另请参阅

类别

标签

产品

Community Treasure Hunt

8 个评论
显示 6更早的评论隐藏 6更早的评论

2 个评论
显示无隐藏无