How to scan through a cell array with mixed data types based on a specific index condition and changeable row size?

Hello everyone,

In the attachment you will see a cell array with text and value as well as intended empty spaces shown as brackets [].

I wanted to achieve the following task, but I am unable to properly excute or write a decent code:

1.) In the first step I want to extract each row index from the attachment right before the string 'EndCurve' and brackets [] appear (Condition 1 for the indexing process):

Fig.1 Example Cutout of the provided data set

As seen above in the above cutout, the index that I would like to get here in the cutout is 189. The following index contains a string as well as a brackets hence it does not meet my index condition. The above cutout is just a small part of the data. However I want to get the all the indices which meet that condition mentioned in point 1.).

A.)In order the solve this I got the following idea:

b.) Get all the indices from each block (value range of the numerical data until the 'EndCurves' as string data type )

c.) Substract the last index with 1 in order to get the desired index value

D.) Problem:

I am unable to "scan" the the mentioned blocks since the rows of each block are not consistent.

Therefore I would like to ask you, if there is a "simple" way to write such a code which...

"scans" through the rows,

performs the the ideas mentioned in point c.) and d.)

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I would really appreciate it if you could contribute to this solution!!! Or even come up with a better approach. If you could, mention your thought process from start to finish since this method helped me a lot with other tasks, please. I also wanted to thank everyone for the previous answers and patience with my demands.

Notice & Background informations (In case anyone asked me about the purpose):

I am currently dealing with a project that evaluates the communication between 3D printer, MatLab and Excel. Therefore I am currently writing a MatLab Subroutine in order to run it as a "communication tool". I am currently at the final stage of this project. The probably biggest obstacle is now the fact, that I need to secure a communication for the 3D printers. This leads me to the solution of writing a macro with the suitable 3D printer execution language. My questions originates from the problem that all printer need a different amount of rows in order to initiate the "start printing" command. So if I would knew the index, i could set up a "border" for my macro which separates the numeric values as well as the string data types.

So if you could help me with my little problem I would be able to "tell" each of 3D printers which row is responsible for the "starting command"

Answer 1

[Jan]

In the first step I want to extract each row index from the attachment right before the string 'EndCurve'

% Assuming that your cell array is called C:
index = find(strcmp(C(:, 1), 'EndCurve')) - 1

[David Mrozek]

Ok so you just used strcmp to compare strings, right? Well its a one liner again. But I have a few addional questions for the purpose of understanding your code:

a.) Does strcmp automatically converts each element into a string and executes them if the string length of both values agree?

b.) If I were to replace the 'EndCurve' string with 'StartCurve' and add 1 than I would get the index after the string 'StartCurve'?

[Stephen23]

a) No. strcmp does not "convert" any data. Based on tests I performed recently for another project, strcmp ignores all data types that are not string or char (possibly in a cell array)**. strcmp does not "execute" anything: there are no function handles or executable code involved as arguments to strcmp. The length (i.e. number of characters) is only relevant because a different number of characters means that the two inputs clearly do not match (presumably strcmp does this trivial check early in its processing).

b) Probably. Did you try it?

** as far as I can tell, this behavior is undocumented. Even numeric values are ignored, not even considered as character codes:

+'a'

ans = 97

strcmp(97,'a')

ans = logical
   0

[David Mrozek]

Yes, works perfectly. Thank you again for the brief and enriching insight!!