How to count here?

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Chathu
Chathu il 22 Gen 2015
Commentato: Chathu il 22 Gen 2015
Here is what i originally have:
'No.' 'Time'
'2011' '119.823011000'
'2012' '119.923206000'
'2013' '120.023454000'
'2014' '120.122663000'
'2015' '120.222851000'
'2016' '120.323050000'
'2017' '120.422283000'
'2018' '120.522470000'
'2019' '120.622677000'
'2020' '120.721896000'
'2021' '120.822124000'
'2022' '120.922356000'
'2023' '121.021516000'
'2024' '121.121760000'
'2025' '121.221989000'
In the Time column, i want to find the count till time < 121.000000000.
This is what i wrote:
No=floating(data{2}<121.000000000);
count=sum(~No)
But i got an error.

Risposta accettata

Stephen23
Stephen23 il 22 Gen 2015
Modificato: Stephen23 il 22 Gen 2015
You code is almost right, just the function floating is not known to MATLAB. It doesn't exist, unless you have written it yourself, and using it probably gives you an error ("Undefined function..."). But that is alright, the data class of data{2} values is not really very important anyway, as the < operator is defined for all numeric classes anyway, as well as logical and character arrays. Try this:
idx = data{2} < 121;
sum(~idx)
The documentation states the applicable data types for the lt operator. Tip: Have a look at the "Contents" panel on the left-hand side of the webpage. Explore it for a few minutes: this is a really great way to find related functions, and to explore what you can do with particular classes of data. Get comfortable with using these "Contents" and using MATLAB becomes a lots more fun and interesting!
  1 Commento
Chathu
Chathu il 22 Gen 2015
@ Stephen- it works. Thank you so much.
In addition, thanks alot for the extra piece of information.

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Più risposte (1)

David Sanchez
David Sanchez il 22 Gen 2015
If you want to sum over the second column of your cell array untill the value of the cell is equal or greater to 121:
Since you have to start counting from your second row (first row is the variable name)
your_sum = 0; % initialize your summation
for k=2:size(your_cell,1)
if str2double(your_cell{k,2})>= 121
break
end
your_sum = str2double(your_cell{k,2}) + your_sum;
end
  1 Commento
Chathu
Chathu il 22 Gen 2015
@ David- thanks alot for your response. Can you kindly tell me what does "your_cell" refers in your For loop? i guess it's the time column,correct?

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