How to compare column values of two rows from a cell and report the third row(labes) according to the comparsion

How can I write the code of these two desired output for this problem?

The problem is that there are a Shopping List(items) which is a string array and a Price List which is numerical array, both with the same length since each price is assigned to an item. so for instance, we have:

ShoppingList = ["apple" , "orange" , "bread" , "milk" , "butter" , "crackers" , "carrots" , "zuchine" , "pasta" , "wine"];

PriceList = [12 25 10 20 1 10 15 18 5 11];

Then we want to set a value as a threshold(THR) that if any given price is higher than that, we decide to not buy it; so that then:

1) In our cell, we would have a new row with reported values of 0 or 1 for "not buy" or "buy" assigned to each item according to the price threshold

2) Extract a new string array in which all the reported items have a price less than threshold.

So far I coded in this way to build a cell with 3 rows for comparison and data exctraction ...

ShoppingList = ["apple" , "orange" , "bread" , "milk" , "butter" , "crackers" , "carrots" , "zuchine" , "pasta" , "wine"];
PriceList = [12 25 10 20 1 10 15 18 5 11];
prompt = "How much money do you want to spend on each item of the list?";

THR = input(prompt) % threshold setting
THR_array = repelem(THR, 10) % Make the thresold value into an array with the same length as the other two arrays

CELL = [num2cell(ShoppingList) ; num2cell(PriceList) ; num2cell(THR_array)] % a cell with 3 rows

But I don't know how to build that 0/1 vector as a new row of the cell accodring to the threshold as well as how I can report the items (from the first row) which has a price below the threshold ...

I appreciate a clear respone to have these two outputs. Also if there is any other way to get this output in a more simpler way, I would like to know how! Thank you!

[Tommy]

Use single quotes rather than double quotes for your input:

prompt = 'How much money do you want to spend on each item of the list?';

Additionally, there is no need for repelem. You can compare each value within PriceList to a single value, and MATLAB will give you your vector of 1s and 0s:

>> PriceList<10

ans =

  1×10 logical array

   0   0   0   0   1   0   0   0   1   0

Read up on logical indexing in order to obtain the trimmed shopping list.

[Amin S]

Thank you very much for the shortcut way!

and what would be the direct algorithm of comparing and filtering the columns of a row (ShoppingList in this case) based on the column's values of another row(PriceList in this case) in a cell to see which columns reach to a specific threshold?

Is it possible at all to do such comparsions in a cell or is it only possible in matrices?

[Sindar]

What size do you expect your cell array to be?

[Amin S]

I'm not sure, for this example it is very short, but in general something normal. Why? How does the size related?

[Tommy]

DId you look into logical indexing? Discussed at the bottom of this page:

https://www.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html

If I have a cell array, say

>> a = cellstr(('a':'j')')'

a =

  1×10 cell array

    {'a'}    {'b'}    {'c'}    {'d'}    {'e'}    {'f'}    {'g'}    {'h'}    {'i'}    {'j'}

as well as the logical array from my first comment:

>> PriceList<10
ans =
  1×10 logical array
   0   0   0   0   1   0   0   0   1   0

then indexing into my cell array with the logical array gives the following output:

>> a(PriceList<10)

ans =

  1×2 cell array

    {'e'}    {'i'}

[Amin S]

Ah I see... all I needed was only logical indexing! thank you! now it works!