Replace values in table from a second table

I have a variable-sized table, created automatically by a simulink callback at the end of a simulation. This extracts all the logged signals, and creates a table with their corresponding variable names.

After this, I need to replace certain values with certain strings. The idea is to have a second table with two columns: First column is a number, second column is a text string.

I need to write a code that:

1. Reads all the numbers in column 1 of the second table and sees if there is a match in all the cells of table number one.
2. If there are matches, to replace the value found in table number one with the text string from table number two that shares the row of the reference value.

I have been trying some combination of codes, but failed miserably so far.

Any thoughts on this would be great.

Thanks!

[Jan]

Please start with explaining, if "table" means a table object, a matrix, an Excel file or something else.

[Rodolfo Villanueva]

It means a table object

[Jan]

Please post a small example for the inputs and wanted output. I'm confused by this detail: "The idea is to have a second table with two columns: First column is a number, second column is a text string." As far as I understand, you do not have the 2nd table, do you? Then How can you read all numbers in its first column? What should happen, when a number is not found?

Answer 1

[madhan ravi]

help strcmp

[Rodolfo Villanueva]

Using strcmp would mean to write endless lines of code and would probably very slow.

[Jan]

@Rodolfo Villanueva: I do not think so. Because strcmp is very fast and I assume a small loop is sufficient already, I expect this is an efficient solution.

Answer 2

[Peter Perkins]

This sounds like in general you'd want a join operation. Hard to say without details.

>> t1 = table([1;2;3;4],["a"; "b"; "c"; "d"])
t1 =
  4×2 table
    Var1    Var2
    ____    ____
     1      "a" 
     2      "b" 
     3      "c" 
     4      "d" 
>> t2 = table([2;4;6],["bb"; "dd"; "ff"])
t2 =
  3×2 table
    Var1    Var2
    ____    ____
     2      "bb"
     4      "dd"
     6      "ff"
>> t3 = outerjoin(t1,t2,'Key','Var1','Type','left')
t3 =
  4×4 table
    Var1_t1    Var2_t1    Var1_t2     Var2_t2 
    _______    _______    _______    _________
       1        "a"         NaN      <missing>
       2        "b"           2      "bb"     
       3        "c"         NaN      <missing>
       4        "d"           4      "dd"     
>> fromT2 = ~isnan(t3.Var1_t2)
fromT2 =
  4×1 logical array
   0
   1
   0
   1
>> t1.Var2(fromT2) = t3.Var2_t2(fromT2)
t1 =
  4×2 table
    Var1    Var2
    ____    ____
     1      "a" 
     2      "bb"
     3      "c" 
     4      "dd"