change the first digits when ends with 5959

Hey, I've got a doubt. I have a string of numbers that go from 0000 to 5959(First two are the minuts and the other two the seconds), when it reaches another time 0000 I wanted to add a unit that goes from 1 to 23(that indicates the hours). I have added this line of code:

T_Hour_1 = '00'+t1; % it gives us t1 with two 00 that indicates the hour

then I got this lines of code that changes the string of T_Hour_1 to dur.

DN1 = str2double(t1);
dur1 = minutes(floor(DN1/100)) + seconds(mod(DN1,100)); % separar en minutos y segundos
[~, M1, S1] = hms(dur1); % Dar tiempo en 2 variables, utilizar M1 para crear rangos

Before doing DN1 I would like to add the numbers from 0 to 23 in front of the others.

How could I do it?

Thank you for your help!!

Answer 1

[Stephen23]

Rather than messing around with strings you should probably just work with duration objects or numeric arrays.

S = ["000000";"000059";"000100";"000159";"005959";"000000";"005959";"000000";"005900"]

S = 9×1 string array
    "000000"
    "000059"
    "000100"
    "000159"
    "005959"
    "000000"
    "005959"
    "000000"
    "005900"

D = duration(strcat(extractBefore(S,3),':',extractBetween(S,3,4),':',extractAfter(S,4)))

D = 9×1 duration array
   00:00:00
   00:00:59
   00:01:00
   00:01:59
   00:59:59
   00:00:00
   00:59:59
   00:00:00
   00:59:00

D = D + hours(cumsum([0;diff(D)<0]))

D = 9×1 duration array
   00:00:00
   00:00:59
   00:01:00
   00:01:59
   00:59:59
   01:00:00
   01:59:59
   02:00:00
   02:59:00

[Stephen23]

If the original strings only include hour and minute data then you can simplify the code:

S = ["0000";"0059";"0100";"0159";"5959";"0000";"5959";"0000";"5900"]

S = 9×1 string array
    "0000"
    "0059"
    "0100"
    "0159"
    "5959"
    "0000"
    "5959"
    "0000"
    "5900"

D = duration(strcat('00:',extractBefore(S,3),':',extractAfter(S,2)))

D = 9×1 duration array
   00:00:00
   00:00:59
   00:01:00
   00:01:59
   00:59:59
   00:00:00
   00:59:59
   00:00:00
   00:59:00

... etc

[flashpode]

hey the way you did before was okay. Now it gives me error.

Thank you for the help.

[flashpode]

could you explain to me the second line of code you gave me. I do not understand and maybe I use it another time for the days.

D = D + hours(cumsum([0;diff(D)<0]))

[Stephen23]

"could you explain to me the second line of code you gave me"

That line locates where the difference in duration is negative (i.e. the duration jumps from a larger value to a smaller value). It then uses CUMSUM on those jump points to create a vector of hourly increments.

If you do not understand how code works then take it apart and look at all of the intermediate results:

S = ["0000";"0059";"0100";"0159";"5959";"0000";"5959";"0000";"5900"];
D = duration(strcat('00:',extractBefore(S,3),':',extractAfter(S,2)))

D = 9×1 duration array
   00:00:00
   00:00:59
   00:01:00
   00:01:59
   00:59:59
   00:00:00
   00:59:59
   00:00:00
   00:59:00

V = diff(D) % difference between adjacent durations.

V = 8×1 duration array
    00:00:59
    00:00:01
    00:00:59
    00:58:00
   -00:59:59
    00:59:59
   -00:59:59
    00:59:00

W = V<0 % locations where longer duration jumps back to shorter duration.

W = 8×1 logical array
   0
   0
   0
   0
   1
   0
   1
   0

X = [0;W] % pad with zero.

X = 9×1

0 0 0 0 0 1 0 1 0

Y = cumsum(X) % create numeric list of hourly jumps

Y = 9×1

0 0 0 0 0 1 1 2 2

Z = hours(Y) % convert to duration.

Z = 9×1 duration array
   0 hr
   0 hr
   0 hr
   0 hr
   0 hr
   1 hr
   1 hr
   2 hr
   2 hr

D = D + Z % add to the original data

D = 9×1 duration array
   00:00:00
   00:00:59
   00:01:00
   00:01:59
   00:59:59
   01:00:00
   01:59:59
   02:00:00
   02:59:00

Answer 2

[Steven Lord]

Is there a reason you're starting with string data first rather than using a duration array from the start?

d = minutes(0:0.25:60);
d.Format = 'hh:mm:ss';
d(1:5)

ans = 1×5 duration array
   00:00:00   00:00:15   00:00:30   00:00:45   00:01:00

d(end-4:end)

ans = 1×5 duration array
   00:59:00   00:59:15   00:59:30   00:59:45   01:00:00

[flashpode]

Because I get those numbers from a string. Then with the code I wrote I chage it to a number array but with the function str2double the 00 desappear. That is why I wanted to change them before that. As you can see in the image after 005959 It goes another time to 000000 I want to get a 010000

[Stephen23]

STR2DOUBLE is not really suitable for handling date/time values written as one string of digits.

You should be using duration objects to store time durations.