How do I extract a number from a string?

Question

Pedro Guevara 2019-6-22

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https://ww2.mathworks.cn/matlabcentral/answers/468414-how-do-i-extract-a-number-from-a-string

编辑： per isakson 2019-6-22

Good afternoon. I have the following problem. I have a matrix of type "Cell" in which there is data of type "string", said data is composed of a non-numeric character (a - U-) and a numeric character. I want to extract the numeric character of each of the cells in the matrix. Below I leave some images of how my matrices are made.

I want to extract the numerical values of all the "cells" of the last column.

the matrix is named "Yp_c"

Thank you.

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per isakson 2019-6-22

I prefer downloading code/variables, which can be used in testing. Please upload Yp_c and possible more examples in a mat-file.

Pedro Guevara 2019-6-22

在 MATLAB Online 中打开

I only have this scheduled mars.

Zi= zeros(1,NP); 
Zi_c = cell(2,NP);
menospiso =0; 
Coe_par=Coe_par; %--->COE DE PART MODAL (R): DEL PASO 6.  Del el modo mas Bajo al mas Alto. 
Modos_C=Modos_C;
Yp = zeros(NP,NP); 
Yp_c= cell(NP+1,NP+1);
NodosT1= sortrows(unique(NodosT(:,2)),'descend');
NodosT= sortrows(NodosT,2,'descend');
%--->Despla Max y Despla translacionales
for f=1:NP    
    
 [Pos_GL_Y1] = find( NodosT (:,2)  ==   NodosT1(f,1) ); 
 [Minx_piso,Pminx]= min( NodosT(  Pos_GL_Y1,1  ) ); 
 Zi (:,f) = abs( Coe_par(f,1) )* M_Sd(f,1); % desplazamientos
 Zi_c (:, f) =  [ num2cell( Zi (:,f)  ) ;  ['Mod',num2str(f)]  ]  ;
 Yp(:, f)= Modos (:,f)*Zi(1,f);
 Yp_c (:, f) =  [ num2cell(Yp(:, f)) ; ['Mod',num2str(f)]  ]  ;
 Yp_c {f, NP+1} =    ['U ',num2str(  NodosT  ( Pos_GL_Y1 (Pminx,1) , 3  )  )]    ;   
 menospiso=menospiso+1; 
 
end

Thank you

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Answer 1

per isakson 2019-6-22

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/468414-how-do-i-extract-a-number-from-a-string#answer_380369

编辑：per isakson 2019-6-22

在 MATLAB Online 中打开

Try this %%-section by section

%%
cac = { 123, 'U 2'; 'Mod3', 789 }; % Sample data
%%
isx = cellfun( @(chr) isa(chr,'char'), cac );
%% 
buf = regexp( cac(isx), '\d+', 'match' ); 
num = cellfun( @str2double, buf, 'uni',false );
%%
cac(isx) = num;

and peek on the result

>> cac
cac =
  2×2 cell array
    {[123]}    {[  2]}
    {[  3]}    {[789]}
>> 

After reading "all the "cells" of the last column" more carefully

%%
cac = { 123, 'U 2'; 'Mod3', [] }; % Sample data
%%
isx = cellfun( @(chr) isa(chr,'char'), cac(:,end) );
%% 
buf = regexp( cac(isx,end), '\d+', 'match' ); 
num = cellfun( @str2double, buf, 'uni',false );
%%
cac(isx,end) = num;

and peek on the result

>> cac
cac =
  2×2 cell array
    {[ 123]}    {[       2]}
    {'Mod3'}    {0×0 double}

/ R2018b

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Answer 2

Fikret Dogru 2019-6-22

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Hello,

I didn't get your question well but if you want to extract numerical value try cell2mat first or use cell string to get values like Yp_c{:,:} all elements