Help with changing text in a table

Dear Sir/Madam,

I am fairly new to matlab and im having a problem with converting text in my table to different names. I have a table called X and under the column 'StepID' I have repeated characters of 'a to h' (8000 rows). I would like to change 'a' to 'protein A' and 'b' to 'VI' and 'c' to a different a name and so and and so forth until h. How could I implement this in Matlab.

Any help is greatly is greatly appreciated (using R2020b)

Best Regards,

Jeevs S

Answer 1

[dpb]

tSingh=readtable('singhData.xlsx');
catnames={'Protein A','VI','DI','AN', 'UF','CA','VRF','DF'};
tSingh.Step=categorical(tSingh.StepID,unique(tSingh.StepID),catnames);

results in

>> head(tSingh)
ans =
  8×3 table
    StepID      M        Step   
    ______    _____    _________
    {'a'}      0.00    Protein A
    {'b'}      0.00    VI       
    {'c'}      0.00    DI       
    {'d'}      0.00    AN       
    {'e'}      0.00    UF       
    {'f'}      0.00    CA       
    {'g'}     10.00    VRF      
    {'h'}      5.71    DF       
>> 

You can, of course, replace 'StepID' in place if don't need the original any longer...

NB: the shorthand to get the valueset list instead of the constructed list...it's cleaner and is also sorted by unique()

Answer 2

[dpb]

It's always bestest to attach a short section of your file/variable that illustrates...but will take a stab at it from the description.

Sounds like a place for a categorical variable instead of just string substitution -- try

catnames={'Protein A','VI', ...};           % DEFINE THE display names for each category
tX.Step=categorical(cellstr(tX.Step),cellstr(['a':'h'].'),catnames);

You didn't provide the full list; you'll have to create it to match as desired...

[gurjeevan singh]

Dear dpb,

Thank you for getting back to me. Apologies for not putting in the full list.

The full list is:

catnames={'Protein A','VI','DI','AN', 'UF','CA','VRF','DF'};

I have now attatched the table is to the original question post.

I have tried you solution, however, Im getting the following error; is there something Im doing wrong ?

I have called my table massloss, which shows in the below error.

massloss.StepID=categorical(cellstr(massloss.StepID),>> cellstr(['a':'h'].',catnames);

↑

Error: Invalid use of operator.

Thank You,

Jeevs S

[dpb]

That's a fignewton of the cut' n paste from the command line I didn't see...the ">>" command prompt doesn't belong in there; not sure how it did get there, but..

catnames={'Protein A','VI', ...};           % DEFINE THE display names for each category
tX.Step=categorical(cellstr(tX.Step),cellstr(['a':'h'].'),catnames);

will have a much better chance....

[gurjeevan singh]

Thank you SO much ! It worked ! yay! saviour !

Best, Jeevs S