Index exceeds matrix dimensions error

Question

Justin Howard 2018-4-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/393957-index-exceeds-matrix-dimensions-error

回答： dpb 2018-4-10

I'm trying to get my for loop to display the names that have systolic blood pressure over 90, but i get an error on the line with my fprintf statement saying my index exceeds matrix dimensions. im not sure what else to do?

data=textscan(fid,'%s%s%d%d','delimiter', '/');
Names=data(:,2);
Systolic=data(:,3);
Diastolic=data(:,4);
n=length(Systolic);
for i=1:length(n)
  if (Systolic{i} > 90)
    fprintf('%s is ideal',Names{:,2});  
  end 
end

2 个评论
显示无隐藏无

David Fletcher 2018-4-10

在 MATLAB Online 中打开

look at this on the second line

Names=data(:,2)

Now look at this in your fprintf statement

fprintf('%s is ideal',Names{:,2});

Do you see the problem?

Justin Howard 2018-4-10

yes but even when i change it, it still pulls up the same error.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

dpb 2018-4-10

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/393957-index-exceeds-matrix-dimensions-error#answer_314427

在 MATLAB Online 中打开

In Matlab, no loops needed--

data=textscan(fid,'%s%s%d%d','delimiter', '/'); 
Names=string(data(:,2));           % convert to string instead of cell array
Systolic=data{:,3};                % and to double array
Diastolic=data{:,4};
SystThresh=90;                     % don't bury "magic numbers in code; make variables
isOK=(Systolic > SystThresh)       % logical addressing array of condition
fprintf('%s is ideal\n',Names(isOK));  % use the vector, Luke!

I'd suggest also look at readtable in lieu of textscan to get data as a table; much advantage there in processing by a variable name and in lookups for classifying by various variables, conditions...