File:Delta t.svg
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Size of this PNG preview of this SVG file: 640 × 480 pixels. Other resolutions: 320 × 240 pixels | 1,024 × 768 pixels | 1,280 × 960 pixels | 2,560 × 1,920 pixels.
Original file (SVG file, nominally 640 × 480 pixels, file size: 36 KB)
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Summary[edit]
| Description |
English: Plot of ∆T = TT − UT as a function of time, where TT is Terrestrial Time and UT is Universal Time. This plot combines the data sets Historic Delta T and LOD (1657.0 – 1973.0) and Monthly determinations of Delta T (from 1973-02-01 onwards) from the IERS Rapid Service/Prediction Center. |
| Date | |
| Source | Own work |
| Author | Musashiaharon |
| Other versions |
Delta T.jpg:  (1657 – 1984), TT-UT function of time.png:  (1657 – 1994), Delta T 1657-2022.svg:  (1657–2022) |
Source[edit]
#!/bin/sh
tail -n +3 historic_deltat.data |
awk '{ print $1 "\t" $2; } /1973/ { exit; }' > hist.data
awk '
{
# use gdate on osx after brew install coreutils. On linux, use date.
doy = "gdate +%j --date=" $1 "-" $2 "-" $3; doy |getline dayOfYear; close(doy)
diy = "gdate +%j --date=" $1 "-12-31"; diy |getline daysInYear; close(diy)
printf("%0.3f\t%s\n", $1 + ((dayOfYear - 1)/daysInYear), $4);
}' < deltat.data >> hist.data
#!/usr/bin/env gnuplot
set terminal svg size 640, 480 name "Delta_t"
set output 'Delta_t.svg'
set title "∆T = TT − UT"
set xlabel "year"
set ylabel "∆T (s)"
set grid linetype 1 linecolor rgb "#cccccc"
unset key
set style data lines
set style line 1 linetype 1 linewidth 2
set style increment user
set xzeroaxis linetype 2 linecolor rgb "black"
plot 'hist.data' linetype rgb "#FF0000"
Licensing[edit]
I, the copyright holder of this work, hereby publish it under the following license:
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
File history
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 07:31, 30 August 2022 | | 640 × 480 (36 KB) | Musashiaharon (talk | contribs) | Updated to include up to 2022-02-01 |
| 05:12, 7 May 2018 |  | 640 × 480 (32 KB) | Musashiaharon (talk | contribs) | Slight alignment fix to post-1973 data, assuming data measured at midnight on the first of each month. | |
| 04:13, 7 May 2018 |  | 640 × 480 (32 KB) | Musashiaharon (talk | contribs) | Includes data up until 2018.0 | |
| 13:22, 13 October 2015 |  | 640 × 480 (28 KB) | Edgar.bonet (talk | contribs) | User created page with UploadWizard |
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