read textfile in Matlab -

i quite stuck matlab problem here.. have *.txt file looks this:

1

2

2

x50

2

2

2

x79

which means @ coordinates (1,2,2) f(x)-value 50 , @ coordinates (2,2,2) f(x)-value 79. trying read matlab have vector (or using repmat meshgrid-like matrix) x , 1 y. not need z since not change on process. want read in f(x)-value can plot whole thing using surf().

if use

   [a] = textread('test.txt','%s')  

it gives me whole thing... can give me idea please? thinking putting thing in loop, pseudocode

   i=1 50    xpos = read first line    ypos  =read next line    zpos = read next line (or ignore.. however..)    functionvalue= read next line    end 

any hints? thanks

assuming data setup in text file lines 1,2,3 xyz coordinate points , next line (fourth line) function value. 5,6,7 next set of xyz coordinate points followed function value on 8th line set , on such repeating format, see if works -

%// read data text file text_data = textread(inputfile,'%s')  data = reshape(text_data,4,[])  %// numeric data data(end,:) = strrep(data(end,:),'x','') %// or  data(end,:) = arrayfun(@(n) data{end,n}(2:end),1:size(data,2),'uni',0) data_numeric = str2double(data)  %// separate xyz , function values xyz = data_numeric(1:3,:)' %//'# each row hold set of xyz coordinates f_value = data_numeric(end,:) %// function values 

---

a bit more robust approach -

%// read data text file txtdata = textread(inputfile,'%s');  %// ----------- part i: xyz --------------------- %// find cell positions first character digit indicating %// these cells containing coordinate points digits_pos_ele = isstrprop(txtdata,'digit'); digits_pos_cell = arrayfun(@(x) digits_pos_ele{x}(1),1:numel(digits_pos_ele));  %// convert numeric format , reshape have each row holding each set %// of xyz coordinates xyz_vals = reshape(str2double(txtdata(digits_pos_cell)),3,[])'; %//'  %// ----------- part ii: function values --------------------- %// find positions cell start `x` indicating these %// function value cells x_start_pos = arrayfun(@(n) strcmp(txtdata{n}(1),'x'),1:numel(txtdata));  %// collect function value cells , find function value %// themeselves excluding first character cells f_cell = txtdata(x_start_pos); f_vals = str2double(arrayfun(@(n) f_cell{n}(2:end), 1:numel(f_cell),'uni',0))'; %//'  %// error checking if size(xyz_vals,1)~=size(f_vals,1)     error('woops, not right!') end