i have excel sheet 31 coulmn,, the first coulmn is time and in the other coulmns the signals names , what i need from the code is that at spefic time to tell me for examplk

i have excel sheet 31 coulmn,, the first coulmn is time and in the other coulmns the signals names , what i need from the code is that at spefic time to tell me for example how many ones are there and which samples of the 31 are the one at that time , how to that ?

[Walter Roberson]

What do you want to do if the specific time does not exactly appear in the file? For example suppose that you ask about 17:09:23 but it turns out that the file only has 17:09:23.491 or 17:10:00 ?

[Hagar Hendy]

lets assume that there is no floating point. at specsifc time such as 5.00ns

[Walter Roberson]

Are the entries in the first column integers that represent nanoseconds ? You write 5.00ns but that implies potential problems if the file has 4.9995 ns or the user asks for 6 ns when you only have times in 5 ns increments (for example)

[Hagar Hendy]

i get that table from another program , and i know the at which time the signal is one, so acording to that , i am choosing that spesfic time, , my concerns is how to know that this signal is one , not only the counting , i want to know the signal name that is 1 out of the 30

Answer 1

[Walter Roberson]

Given a particular scalar row index (calculated from the time, perhaps):

VarNames = YourTable.Properties.VariableNames;

ValuesAtIndex = YourTable{RowIndex, 2:end};
match_columns = 1 + find(ValuesAtIndex == 1);
matched_signal_names = VarNames(match_columns);

matched_signal_names will be a cell array of character vectors. It will be empty if there are no matches, and might have multiple entries if there are multiple matches.

[Hagar Hendy]

In this command line that is below, should i change th your yable to the name of the excel sheet ? and .variable name , is it built in function ? or ihave to change it and put the name of sheet?

VarNames = YourTable.Properties.VariableNames;

also this error shown

[Walter Roberson]

"i have excel sheet 31 coulmn"

You cannot use load() to load a .xls or .xlsx -- it will complain about the file being in an unknown format.

You can use load() to load a .csv file only if the .csv file is pure numeric, or pure numeric with comma delimiter, or if all lines that have text begin with % in the very first column.

If you have a .csv file that has a text header that does not happen to have % as the very first character, you cannot use load() to read the file.

To read a .csv file, you need to use one of readtable (if it has entries that are not pure numbers), or readmatrix (entries other than the headers must be pure numbers), or dlmread or csvread specifying the number of headerlines; or using one of the lower-level routines such as fopen + textscan

[Peter Perkins]

In recent versions, if time is involved, use readtimetable. Then use time subscripting on the timetable, and beyond that, I can't tell what the question is.