matlab function replacing last part of strings between known characters - string

Question

I have a text file TF including a set of the following kind of strings:
"linStru.twoZoneBuildingStructure.north.airLeakage.senTem.T",
"linStru.twoZoneBuildingStructure.north.vol.Xi[1]",
"linStru.twoZoneBuildingStructure.south.airLeakage.senTem.T",
"linStru.twoZoneBuildingStructure.south.vol.Xi[1]", "
"linStru.twoZoneBuildingStructure.north_ext.layMul.nMat[1].monoLayer1Nf.T[1]",
"linStru.twoZoneBuildingStructure.north_ext.layMul.nMat[1].monoLayer2Nf.T[2]",
Given a line L, starting from the end let the substring s denote the portion of the string between ," and the first .
To make it clearer, for L=1: s=T, for L=2: s=Xi[1], for L=5: s=T[1], etc.
Given a text file TF in the above format, I want to write a MATLAB function which takes TF and replaces the corresponding s on each line with der(s).
For example, the function should change the above strings as follows:
"linStru.twoZoneBuildingStructure.north.airLeakage.senTem.der(T)",
"linStru.twoZoneBuildingStructure.north.vol.der(Xi[1])",
"linStru.twoZoneBuildingStructure.south.airLeakage.senTem.der(T)",
"linStru.twoZoneBuildingStructure.south.vol.der(Xi[1])", "
"linStru.twoZoneBuildingStructure.north_ext.layMul.nMat[1].monoLayer1Nf.der(T[1])",
"linStru.twoZoneBuildingStructure.north_ext.layMul.nMat[1].monoLayer2Nf.der(T[2])",
How can such a function be written?

Answer 1

Something like
regexprep(TF, '\.([^.]+)",$', '.der($1)",', 'dotexceptnewline', 'lineanchors')
It finds the longest sequence of non-dot characters appearing between a dot before and quote-comma-endline after, and encloses that inside der( ).

Answer 2

I see there is a small " typo on the fourth line of your text file. I'm going to remove this to make things simpler.
As such, the simplest way that I can see you do this is iterate through all of your strings, remove the single quotes, then find the point in your string where the last . occurs. Extract this substring, then manually insert the der() in between this string. Assuming that those strings are in a text file called functions.txt, you would read in your text file using textread to read in individual strings. As such:
names = textread('functions.txt', '%s');
names should now be a cell array of names where each element is each string encapsulated in double quotes. Use findstr to extract where the . is located, then extract the last location of where this is. Extract this substring, then replace this string with der(). In other words:
out_strings = cell(1, numel(names)); %// To store output strings
for idx = 1 : numel(names)
%// Extract actual string without quotes and comma
name_str = names{idx}(2:end-2);
%// Find the last dot
dot_locs = findstr(name_str, '.');
%// Last dot location
last_dot_loc = dot_locs(end);
%// Extract substring after dot
last_string = name_str(last_dot_loc+1:end);
%// Create new string
out_strings{idx} = ['"' name_str(1:last_dot_loc) 'der(' last_string ')",'];
end
This is the output I get:
celldisp(out_strings)
out_strings{1} =
"linStru.twoZoneBuildingStructure.north.airLeakage.senTem.der(T)",
out_strings{2} =
"linStru.twoZoneBuildingStructure.north.vol.der(Xi[1])",
out_strings{3} =
"linStru.twoZoneBuildingStructure.south.airLeakage.senTem.der(T)",
out_strings{4} =
"linStru.twoZoneBuildingStructure.south.vol.der(Xi[1])",
out_strings{5} =
"linStru.twoZoneBuildingStructure.north_ext.layMul.nMat[1].monoLayer1Nf.der(T[1])",
out_strings{6} =
"linStru.twoZoneBuildingStructure.north_ext.layMul.nMat[1].monoLayer2Nf.der(T[2])",
The last thing you want to do is write each line of text to your text file. You can use fopen to open up a file for writing. fopen returns a file ID that is associated with the file you want to write to. You then use fprintf to print your strings and name a newline for each string using this file ID. You then close the file using fclose with this same file ID. As such, if we wanted to output a text file called functions_new.txt, we would do:
%// Open up the file and get ID
fid = fopen('functions_new.txt', 'w');
%// For each string we have...
for idx = 1 : numel(out_strings)
%// Write the string to file and make a new line
fprintf(fid, '%s\n', out_strings{idx});
end
%// Close the file
fclose(fid);

Answer 3

Another way to do it with regexprep:
str_out = regexprep(str_in, '\.([^\.]+)"$','\.der($1)"');
Example: for
str_in = {'"linStru.twoZoneBuildingStructure.north.airLeakage.senTem.T"'
'"linStru.twoZoneBuildingStructure.north.vol.Xi[1]"'};
this gives
str_out =
'"linStru.twoZoneBuildingStructure.north.airLeakage.senTem.der(T)"'
'"linStru.twoZoneBuildingStructure.north.vol.der(Xi[1])"'