How to extract all the rows which match an specific string column

The data is organized on this way: 4 numeric columns and 3 string columns all of same dimentions. I need to build a matrix which contains all the columns in order to extract the rows who match with and specific geol_unit string.

%this is how i read the data:

[x,y,strike_dir,dip,town,geol_unit,source] = textread('DatosEstructurales_C&S.txt','%f %f %f %f %s %s %s','delimiter',';');

%next step would be to build a matrix to obtain something like:

x                      y         strike_dir       dip        'town'          'geol_unit'            'source'
1191292.27        824768.3           65           60        Medellin        StockAltavista        Microzonificacion_2007
1191237.46        825146.46          200          25        Medellin        StockAltavista        Microzonificacion_2007
1188070.99        825708.745         46           55        Medellin        Dunita                RecargaCyS_2013
1188070.99        825708.745         156          60        Medellin        Dunita                RecargaCyS_2013

The final idea is to find an specific geol unit match and extact all the values.. for example all Dunita values, and get a matrix like:

x                      y         strike_dir       dip        'town'          'geol_unit'            'source'
1188070.99        825708.745         46           55        Medellin        Dunita                RecargaCyS_2013
1188070.99        825708.745         156          60        Medellin        Dunita                RecargaCyS_2013

Answer 1

[KL]

Use readtable to import your data,

 T = readtable('DatosEstructurales_C&S.txt');

if you don't have column names included in your text file, then

 T.Properties.VariableNames = {'x','y','strike_dir','dip','town','geol_unit','source'};

and now to get what you want,

 T_dunita = T(T.geol_unit == 'Dunita',:)

read more about readtable and tables on the below links:

https://de.mathworks.com/help/matlab/ref/readtable.html

https://de.mathworks.com/help/matlab/ref/table.html

[KAE]

When trying to match a string in a table column,

T.geol_unit == 'Dunita'

I get the error

Undefined operator '==' for input arguments of type 'cell'.

[Cristian Miculas]

use "Dunita" instead of 'Dunita' or strcmp(T.geol_unit, 'Dunita')

Answer 2

[Craig]

Use: T_dunita = strcmp(T.geol_unit, 'Dunita')