Find and Replace (MATLAB)
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I am trying to find and replace text string before a comma and keep the data string after the comma. I have tried the wildcard '*' but it didn't work. I have 55 states to do this to. An example is 'Adak Island, AK' to just "AK".
repeats = ' , AK'
indices = strfind(repeats, 'AK')
indices = 4
using_replace = replace(repeats, ' , AK', 'AK')
nothing changed, the text string stayed the same. Any suggestions?
采纳的回答
strip(extractAfter('Adak Island, AK',","))
And see the other fun methods of string to figure out how to manipulate the part you want
methods('string')
3 个评论
Deborah Johnson
2022-6-7
Sean de Wolski
2022-6-7
This will stick it back in as a new variable in the table called State
T = readtable('County_STATE.csv');
T.State = extractAfter(T.DISPLAY_AIRPORT_CITY_NAME_FULL,", ");
Deborah Johnson
2022-6-10
更多回答（4 个）
Try this:
t = readtable('County_STATE.csv');
% Crop off null columns
t = t(:, 1:3);
% Extract State alone, and City alone.
State = extractAfter(t.DISPLAY_AIRPORT_CITY_NAME_FULL, ', ');
City = extractBefore(t.DISPLAY_AIRPORT_CITY_NAME_FULL, ', ');
% Add these on as columns in the table variable.
t = addvars(t, City, State, 'After','DISPLAY_AIRPORT_CITY_NAME_FULL')
Why not just do this:
str = 'Adak Island, AK' ;
commaIndex = strfind(str, ',')
if ~isempty(commaIndex)
output = strtrim(str(commaIndex+1 : end))
else
output = str % No comma in the string so just return the original.
end
4 个评论
Sean de Wolski
2022-6-7
This is the old way predating string behavior in 2016b. I would not recommend it in modern versions.
Deborah Johnson
2022-6-7
编辑：Deborah Johnson
2022-6-7
Image Analyst
2022-6-7
You gave us a character array. Please give us the data in the form of a table in a mat file with the paperclip icon so we can show you how to apply it to a table. Did you try just going down the column row by row?
Deborah Johnson
2022-6-7
Functions like extract, extractAfter, etc. don't modify the variables that you pass in as input. If you were to specify those same variable names as the output argument for those calls then they would be modified.
fruit = "Apple, Banana, Cherry"
The following call creates a new variable named justCherry and leaves the fruit variable with its original contents.
justCherry = extractAfter(fruit, "Banana, ")
fruit
The following call overwrites the existing variable named fruit with the output of extractAfter, so fruit is different after the call.
fruit = extractAfter(fruit, "Banana, ")
fruit
Your original code using_replace = replace(repeats, ' , AK', 'AK') does not modify the repeats variable.
If you'd written repeats = replace(repeats, ' , AK', 'AK') that would overwrite the original contents of the repeats variable with the modified data returned by replace.
Deborah Johnson
2022-6-10
编辑：Deborah Johnson
2022-6-11
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