complex string match with regexprep
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What should be the expression in the following script to generate out from str?
str='diff([v0(k-1,2)-v0(k-1,1) v(2)-v(1)])/diff(t0(k-1:k))+((v(2)-0)*diff(t0(k-1:k))+sum((v0(2:k-1,2)-v0(2:k-1,10)).*diff(t0(1:k-1)).'',1))';
expression = ???;
replace = '0';
out=regexprep(str,expression,replace);
out='diff([v0(k-1,2)-v0(k-1,1) v(2)-v(1)])/diff(t0(k-1:k))+((v(2)-0)*diff(t0(k-1:k))+sum((v0(2:k-1,2)-0).*diff(t0(1:k-1)).'',1))'
7 Comments
Adam Danz
on 14 May 2019
There are so many options with regular expressions that it's hard to capture them all in one document. I usually just google awkward phrases like "regular expressions match any character until" to remind myself of the options. The website I suggested in my answer is another great tool.
Accepted Answer
Adam Danz
on 14 May 2019
Edited: Adam Danz
on 14 May 2019
Here you are.
str='diff([v0(k-1,2)-v0(k-1,1) v(2)-v(1)])/diff(t0(k-1:k))+((v(2)-0)*diff(t0(k-1:k))+sum((v0(2:k-1,2)-v0(2:k-1,10)).*diff(t0(1:k-1)).'',1))';
expression = 'v0\([^,]+,10\)';
replace = '0';
out = regexprep(str, expression, replace)
Compare input/output (I added space in output for comparison)
diff([v0(k-1,2)-v0(k-1,1) v(2)-v(1)])/diff(t0(k-1:k))+((v(2)-0)*diff(t0(k-1:k))+sum((v0(2:k-1,2)-v0(2:k-1,10)).*diff(t0(1:k-1)).',1)) %input
diff([v0(k-1,2)-v0(k-1,1) v(2)-v(1)])/diff(t0(k-1:k))+((v(2)-0)*diff(t0(k-1:k))+sum((v0(2:k-1,2)-0 ).*diff(t0(1:k-1)).',1)) %output
2 Comments
Adam Danz
on 14 May 2019
Edited: Adam Danz
on 14 May 2019
Great! Just so you know...
- v0\( Start the expression at v0(
- [^,]+ Stop matching just before the next comma
- ,10\) make sure the expression ends with ,10)
A nice workstation to develop regular expressions: https://regex101.com/
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