I am trying to plot some data which has time (date) on the x-axis in the format 2015-12-20. I do not want to plot my data against the absolute date, but against the time difference between that date and another reference "zero" date. The reference date is in same format, eg: 2015-12-15.
Is it possible to have the data file in the format:
%Y-%m-%d Value
%Y-%m-%d Value
but have gnuplot create a plot in which the x-axis is number of days since a reference date?
This isn't ideal, and there probably is a better way, but this works (I assume that column 1 is your date column and that column 2 is your y-axis value):
plot "data.txt" u ((strptime("%Y-%m-%d",strcol(1))-strptime("%Y-%m-%d","2015-12-10"))/86400.0):2
The strptime function turns a time string to an internal time representation (the number of seconds since some reference date) and the strcol function reads the string from column 1. We take the difference from the "zero" date (here we use December 10th). This will give the difference in seconds, so we divide by the number of seconds in a day, 86400 (we use 86400.0 so that it doesn't truncate to integers in the division). This will make the x-axis the number of days since the reference date.
Related
The excel column contains Zulu Timzezones How to calculate the difference between two dates in seconds.milliseconds
From Time 2022-04-25T04:16:57.823121842Z
To Time
2022-04-25T04:16:58.173194593Z
2022-04-25T04:16:58.089133751Z
2022-04-25T04:16:58.462278784Z
2022-04-25T04:16:57.829376293Z
2022-04-25T04:16:57.961790312Z
2022-04-25T04:16:58.445884586Z
2022-04-25T04:16:57.830806273Z
2022-04-25T04:16:58.067723338Z
2022-04-25T04:16:58.470913276Z
2022-04-25T04:16:57.838787068Z
When I Try to Do something like =B13-B14
Error
Function MINUS parameter 1 expects number values. But '2022-04-25T04:35:59.092943356Z' is a text and cannot be coerced to a number.
Converted to Number format
REVISED: I forgot to convert the milliseconds
You can convert the date strings into time values by breaking them into parts:
=DATEVALUE(LEFT(A2,10)) + TIMEVALUE( MID(A2,12,8) ) --MID(A2,20,10)/24/60/60
Where A2 is the date string.
This assumes that they have the exact structure that you have shown and fully padded with zeros. If that is not the case, for example the milliseconds could be .095Z, then you can mod this to:
=DATEVALUE(LEFT(A2,10)) + TIMEVALUE( MID(A2,12,8) ) --MID(SUBSTITUTE(A2,"Z",""),20,999)/24/60/60
to be safe.
I'm trying to convert a large time value in excel to a decimal number for hours.
I currently have a column adding up "Ready time" for a call centre which is 3545:20:02 as a SUM. I now want that to show me the same hours in a decimal format e.g. 3545.333 as it's used in another calculation.
For reference, when I convert the above time to a General excel value, it is 147.7222454.
The formula I've been using is: =IFERROR((DAY(M54)*24) + HOUR(M54) + (MINUTE(M54)/60),0) and has been working fine for smaller time values.
Thanks in advance!
Excel counts in days (1 day = 1) so for hours you just multiply by 24, i.e.
=M54*24
format result cell as number with required number of decimals
[the reason your current formula fails is because of DAY function - DAY is day of the month so it fails for you when the time value is >= 32*24 = 768 hours]
I have a date that looks like this text. 17-OCT-16 03.24.11.000000000 AM
I need to format that text into a date that I can then manipulate. Ultimate I want to transform that time to millis from epoch but I'm not sure if that's even possible
Its definitely possible, you can make use of DATEVALUE and TIMEVALUE function which convert a time or date in string format to date/time format:
=DATEVALUE(LEFT(A1,9)) + TIMEVALUE(SUBSTITUTE(MID(A1,11,8), ".", ":")&MID(A1, 19, 9))
This will give you a single number (42660.1417939815) in this case which is the number of days since 1/1/1900 (including milliseconds)
It should just be some simple maths to get total milliseconds
i have a file which looks as follows:
19:40:47,2772
19:41:50,2896
19:42:50,2870
19:43:51,2851
19:44:53,2824
19:45:55,2891
.
.
.
07:52:53,2772
07:53:56,2767
07:55:00,2709
07:56:01,2713
07:57:04,2844
07:58:04,2750
07:59:05,2744
08:00:08,2812
08:01:11,2728
08:02:14,2852
and im trying to do the simple task of making a graph with time X axis & number Y axis.
code as follows:
#!/usr/bin/gnuplot
unset multiplot
set xdata time
set datafile separator ","
set timefmt "%H:%M:%S"
set format x "%H:%M"
set title "defect number"
set xlabel "X"
set ylabel "Y"
plot "Defect_number_03-03-16_08.04.49.csv" using 1:2 w lines
pause -1
problem is that gnuplot autosorts the time and my chart looks like this:
I want to make a chart according to the order in the file, any help will be great =)
When you give the plot command
plot datafile u 1:2
you are telling gnuplot that the first column is your x-value and the second is your y-value. Naturally, earlier times are further to the left (as you didn't post your full data, I have used only the part you did post - this will cause a "skip" in the axis labels).
You can use a pseudocolumn to use the line number as your x-value. The 0 column corresponds to the line number (see help pseudocolumns).
Thus plot datafile u 0:2 will use the line number as the x-coordinate and the 2nd column as the y-coordinate.
We still need to add the correct x-axis labels, and can't rely on them to be generated correctly in this case. We would use the xtic function to do this, as1
plot datafile u 0:2:xtic(1)
which tells gnuplot to use the value in column 1 as an xtic, but it will read this literally and not format it as you have desired with the time. To do this, we can manually cast this to the correct string
plot datafile u 0:2:xtic(strftime("%H:%M",strptime("%H:%M:%S",strcol(1)))) w lines
Here, the strcol function reads column 1 as a string, the strptime function turns this into the internal time representation using the specified format string for reading it, and finally the strftime formats this as time string using the specified output string.
As Christoph stated in his answer, these solutions will cause uniform spacing of the points. If the points are already uniform spaced, this is not a problem, and if the points are very close to uniform spaced, it is probably acceptable as well (it looks like your points are about 1 minute apart give or take a couple of seconds).
However, if we want the absolutely correct spacing, we will need to add a date to the lines. This could be done in the original data file during the creation, or we could use an external process to add the dates only when needed leaving the original file exactly the same.
As you are only marking off the time and not the day in your tic marks, the actual day doesn't matter. It only matters that the times from the next morning are in the next day from the times from the last night.
We can use an external program to add dates. The following python 3 program reads the data file and adds a date to it (using Jan 1st, 2015 for the first date - as previously mentioned this date doesn't really matter). If a time occurs earlier in the day from the previous one, it moves to the next day. Here is the program adddates.py:
from datetime import datetime,timedelta
from sys import argv
last = None
offset = timedelta(days=0)
for x in open(argv[1],"r"):
vals = x.split(",")
dte = datetime.strptime("01/01/2015 "+vals[0],"%m/%d/%Y %H:%M:%S") + offset
if last!=None and last>dte:
offset+= timedelta(days=1)
dte = dte + offset
last = dte
print(dte.strftime("%Y-%m-%d %H:%M:%S"),vals[1],sep=",",end="")
The output from running this on the data file looks like:
2015-01-01 19:40:47,2772
2015-01-01 19:41:50,2896
2015-01-01 19:42:50,2870
2015-01-01 19:43:51,2851
2015-01-01 19:44:53,2824
2015-01-01 19:45:55,2891
...
2015-01-02 07:52:53,2772
2015-01-02 07:53:56,2767
...
We can now read data from this program by opening a pipe in our plot command.
set timefmt "%Y-%m-%d %H:%M:%S"
plot "< adddates.py datafile" u 1:2 with lines
1 Note that this also causes labels to overlap, as it uses all of them. To use every other one, we could have used xtic(int($0) % 2 == 0 ? strcol(1):""). A similar technique can be used with the format using the correct labels as well.
A proper solution is to save your data with full date and time, or as timestamps.
All other solutions with $0 and labelling the xtics with xticlabel requires your data to be spaces equidistantly, which doesn't seem to be the case.
So, just save your data as e.g. UNIX timestamp and you can use all nice gnuplot features without fiddling.
I have the following text timestamp in cell A1. 22-OCT-13 03.40.00.000000000 AM. In B1 I have the following formula: =TIME(HOUR(MID(A1,11,2)),MIN(MID(A1,14,2)),SECOND(MID(A1,17,2))).
It yields 12:40 AM. The hour function returns zero, but the minute function works fine. I can't figure out what's up with it.
MIN is the 'minimum' formula that returns the smallest value out of a list of values, not the MINUTE formula.
I think you are not familiar with TIME(), HOUR() or MINUTE().
TIME() takes 'normal' values and converts them into a time value. If you have TIME(H, M, S), H is the number of hours (not a timestamp), M is the number of minutes (not a timestamp either) and S is the number of seconds (yet again, not a timestamp).
HOUR() takes a time value and extracts the hour from it.
MINUTE() and SECOND() are similar to HOUR(). What you probably meant to have is:
=TIME(MID(A1,11,2),MID(A1,14,2),MID(A1,17,2))
When you use MID() you are getting a number, not a timestamp. So, HOUR takes that number, interprets it as a timestamp and return the hour. In your example, the first MID returns 03. In excel, if you convert that to a timestamp, you get 03/01/1900 00:00 (in dd/mm/yyyy hh:mm format) and the hour is thus 0.
EDIT:
By the way, you could use this formula if you want to keep the date and time (not forgetting the AM/PM at the end:
=SUBSTITUTE(SUBSTITUTE(A1,".",":"),":",".",3)*1
The original date/time is almost one that can be understood by Excel. Replace all . with : and then replace the 3rd (last) : by . and multiply by 1 to tell Excel to convert that to a number. Just format the result as time and that should do it.