I already experienced in this question that the right choice of assignments for the coordinate values and meta values from a table could increase the compilation speed of pgfplots due to the lua backend a lot.
So I just wanted to ask, if someone sees something which could be made faster, mainly in the colormap transformation?
For the compilation of this code, the lua backend is also disabled according to the log, with the message: Package pgfplots info on input line 97: Using 'lua backend=false' for axis: x coord trafo unsupported.. Can this be avoided by changing the point meta code or the code of the colorbar axis transformation, maybe e.g. by using some lua code?
My main problem is the compile time (even though I externalize the images).
With an input data file with non-satisfying resolution (.txt file has about 300 kB), the compilation time is a bit over 3 minutes. With the double sampling rate, the input file has about four times the size, and the compile time increases sixteenfold, which is then almost 1h. (4²=16, which agres with the pgfplots manual statement of quadratic complexity for large datasets) Where does this complexity come from? Is it just the amount of data, or would it get better if the input file is split in several files?
Just the coordinate transformation code:
\pgfplotsset{
symlog colormap trafo/.code={
\pgfkeysalso{%
y coord trafo/.code={%
\pgfmathparse{##1>#1 ? 1+3*ln(##1<#1?1: (##1/#1))/ln(10*sqrt(10)) : (##1<-#1 ? -1-3*ln(##1>-#1?1: (-##1/#1))/ln(10*sqrt(10)) : ##1/#1)}
},
y coord inv trafo/.code={%
\pgfmathparse{##1>1 ? exp((##1-1)/3*ln(10*sqrt(10)))*#1 : (##1<-1 ? -exp((-##1-1)/3*ln(10*sqrt(10)))*#1 : ##1*#1)}
},
}%
},
symlog colormap/.code n args={3}{
\pgfkeysalso{
colorbar style={
symlog colormap trafo={#1},
point meta min={#2},
point meta max={#3},
},
point meta={z>#1 ? 1+3*ln(z<#1?1: (z/#1))/ln(10*sqrt(10)) : (z<-#1 ? -1-3*ln(z>-#1?1: (-z/#1))/ln(10*sqrt(10)) : z/#1)},
}%
},
}
The complete example
\documentclass{article}
\usepackage{xfrac}
\def\infile{infile.txt}
\usepackage{pgfplots}
\usepackage{pgfplotstable}
\pgfplotsset{compat=newest}
\pgfplotsset{
symlog colormap trafo/.code={
\pgfkeysalso{%
y coord trafo/.code={%
\pgfmathparse{##1>#1 ? 1+3*ln(##1<#1?1: (##1/#1))/ln(10*sqrt(10)) : (##1<-#1 ? -1-3*ln(##1>-#1?1: (-##1/#1))/ln(10*sqrt(10)) : ##1/#1)}
},
y coord inv trafo/.code={%
\pgfmathparse{##1>1 ? exp((##1-1)/3*ln(10*sqrt(10)))*#1 : (##1<-1 ? -exp((-##1-1)/3*ln(10*sqrt(10)))*#1 : ##1*#1)}
},
}%
},
symlog colormap/.code n args={3}{
\pgfkeysalso{
colorbar style={
symlog colormap trafo={#1},
point meta min={#2},
point meta max={#3},
},
point meta={z>#1 ? 1+3*ln(z<#1?1: (z/#1))/ln(10*sqrt(10)) : (z<-#1 ? -1-3*ln(z>-#1?1: (-z/#1))/ln(10*sqrt(10)) : z/#1)},
}%
},
}
\begin{document}
\thispagestyle{empty}
\begin{tikzpicture}
\begin{axis}[axis equal image,
xmin=-8,
z buffer = sort,
xmax=8,
ymin=0,
ymax=10,
grid=major,
axis on top,
colorbar,
symlog colormap={142.3}{-4500}{4500},
colormap/viridis,
mesh/ordering=y varies,
view={0}{90},
colorbar style={
scaled ticks=false,
ytick={-4501,-1423,-450,-142.3,0,142.3,450,1423,4501},
yticklabel={
\pgfmathparse{\tick/100}\pgfmathprintnumber[fixed relative, precision=2]{\pgfmathresult}
},
yticklabel style={
align=right,
text width = 1.875em,
},
xlabel = {$E_z \textrm{ in kV/m}$},
xlabel style = {xshift = 0.35cm, yshift = -0.4625 cm},
},
tick label style={/pgf/number format/fixed},
enlargelimits=false,
xlabel={$x \textrm{ in mm}$},
ylabel={$y \textrm{ in mm}$},
]
\pgfplotstableset{skip first n=2}
\pgfplotstableread{\infile}\datatable
\addplot3[
mesh/rows=65,
surf,
shader = interp,
] table [
x index = 0,
y index= 1,
z index = 2;
] from \datatable {};
\end{axis}
\end{tikzpicture}
\end{document}
example infile (truncated)
x [mm] 0
-----------------------------------------------------------------------------------------------------------------------------------------
-8 0 51.0614
-7.75 0 82.8847
-7.5 0 63.4588
-7.25 0 53.413
-7 0 45.8015
-6.75 0 38.6945
-6.5 0 31.5657
-6.25 0 24.3476
-6 0 17.1636
-5.75 0 10.2049
-5.5 0 3.6868
-5.25 0 -2.17792
-5 0 -7.18864
-4.75 0 -11.1697
-4.5 0 -13.9803
-4.25 0 -15.5134
-4 0 -15.7146
-3.75 0 -14.5676
-3.5 0 -12.1229
-3.25 0 -8.48218
-3 0 -3.81099
-2.75 0 1.55382
-2.5 0 7.13892
-2.25 0 12.0255
-2 0 14.4733
-1.75 0 10.3511
-1.5 0 -56.9732
-1.25 0 -57.9164
-1 0 -21.3907
-0.75 0 93.6603
-0.5 0 512.283
-0.25 0 1778.09
0 0 1881.37
0.25 0 1778.09
0.5 0 512.281
0.75 0 93.658
1 0 -21.3938
1.25 0 -57.92
1.5 0 -56.9765
1.75 0 10.3483
2 0 14.4687
2.25 0 12.0195
2.5 0 7.13207
2.75 0 1.54623
3 0 -3.81901
3.25 0 -8.49036
3.5 0 -12.131
3.75 0 -14.5755
4 0 -15.7219
4.25 0 -15.5201
4.5 0 -13.9861
4.75 0 -11.1745
5 0 -7.19197
5.25 0 -2.17986
5.5 0 3.68637
5.75 0 10.2064
6 0 17.1669
6.25 0 24.3528
6.5 0 31.5727
6.75 0 38.7035
7 0 45.8125
7.25 0 53.4264
7.5 0 63.4758
7.75 0 82.9077
8 0 51.0745
-8 0.25 48.8507
-7.75 0.25 71.4631
-7.5 0.25 51.8272
-7.25 0.25 42.4871
-7 0.25 36.1465
-6.75 0.25 30.5903
-6.5 0.25 25.1597
-6.25 0.25 19.6837
-6 0.25 14.2034
-5.75 0.25 8.83354
-5.5 0.25 3.71559
-5.25 0.25 -1.00413
-5 0.25 -5.18482
-4.75 0.25 -8.69938
-4.5 0.25 -11.4425
-4.25 0.25 -13.3293
-4 0.25 -14.3084
-3.75 0.25 -14.3513
-3.5 0.25 -13.4718
-3.25 0.25 -11.714
-3 0.25 -9.15892
-2.75 0.25 -6.01235
-2.5 0.25 -2.57951
-2.25 0.25 0.450236
-2 0.25 1.43912
-1.75 0.25 -4.83268
-1.5 0.25 -42.3624
-1.25 0.25 -38.0751
-1 0.25 16.1594
-0.75 0.25 178.537
-0.5 0.25 748.531
-0.25 0.25 2461.65
0 0.25 2601.04
0.25 0.25 2461.65
0.5 0.25 748.53
0.75 0.25 178.535
1 0.25 16.1563
1.25 0.25 -38.0789
1.5 0.25 -42.366
1.75 0.25 -4.83578
2 0.25 1.43538
2.25 0.25 0.445735
2.5 0.25 -2.58454
2.75 0.25 -6.01804
3 0.25 -9.16484
3.25 0.25 -11.7201
3.5 0.25 -13.478
3.75 0.25 -14.3574
4 0.25 -14.314
4.25 0.25 -13.3345
4.5 0.25 -11.4472
4.75 0.25 -8.70337
5 0.25 -5.1878
5.25 0.25 -1.0061
5.5 0.25 3.71481
5.75 0.25 8.83392
6 0.25 14.2051
6.25 0.25 19.6867
6.5 0.25 25.1642
6.75 0.25 30.5962
7 0.25 36.154
7.25 0.25 42.4966
7.5 0.25 51.8396
7.75 0.25 71.4815
8 0.25 48.8619
-8 0.5 48.7844
-7.75 0.5 67.6708
-7.5 0.5 47.0852
-7.25 0.5 37.682
-7 0.5 31.6811
-6.75 0.5 26.659
-6.5 0.5 21.8645
-6.25 0.5 17.0579
-6 0.5 12.2321
-5.75 0.5 7.45987
-5.5 0.5 2.84438
-5.25 0.5 -1.50177
-5 0.5 -5.46699
-4.75 0.5 -8.94756
-4.5 0.5 -11.8542
-4.25 0.5 -14.1114
-4 0.5 -15.6659
-3.75 0.5 -16.4791
-3.5 0.5 -16.5394
-3.25 0.5 -15.8496
-3 0.5 -14.4255
-2.75 0.5 -12.3673
-2.5 0.5 -9.79737
-2.25 0.5 -6.98801
-2 0.5 -4.6393
-1.75 0.5 -4.80819
-1.5 0.5 -11.6809
-1.25 0.5 8.14997
-1 0.5 78.3415
-0.75 0.5 274.749
-0.5 0.5 943.2
-0.25 0.5 2944.76
0 0.5 3107.5
0.25 0.5 2944.76
0.5 0.5 943.199
0.75 0.5 274.747
1 0.5 78.3391
1.25 0.5 8.14696
1.5 0.5 -11.6839
1.75 0.5 -4.8112
2 0.5 -4.64255
2.25 0.5 -6.99184
2.5 0.5 -9.80156
2.75 0.5 -12.3719
3 0.5 -14.4304
3.25 0.5 -15.8547
3.5 0.5 -16.5445
3.75 0.5 -16.4843
4 0.5 -15.671
4.25 0.5 -14.1161
4.5 0.5 -11.8587
4.75 0.5 -8.95129
5 0.5 -5.47007
5.25 0.5 -1.50406
5.5 0.5 2.84302
5.75 0.5 7.45941
6 0.5 12.2327
6.25 0.5 17.0596
6.5 0.5 21.8673
6.75 0.5 26.6631
7 0.5 31.6865
7.25 0.5 37.6891
7.5 0.5 47.095
7.75 0.5 67.6869
8 0.5 48.7944
-8 0.75 49.6667
-7.75 0.75 67.5706
-7.5 0.75 45.782
-7.25 0.75 35.9227
-7 0.75 29.7622
-6.75 0.75 24.7203
-6.5 0.75 19.9793
-6.25 0.75 15.2548
-6 0.75 10.5115
-5.75 0.75 5.80032
-5.5 0.75 1.2061
-5.25 0.75 -3.17377
-5 0.75 -7.24051
-4.75 0.75 -10.9001
-4.5 0.75 -14.0696
-4.25 0.75 -16.6759
-4 0.75 -18.6636
-3.75 0.75 -19.9861
-3.5 0.75 -20.6155
-3.25 0.75 -20.5269
-3 0.75 -19.6867
-2.75 0.75 -18.1148
-2.5 0.75 -15.773
-2.25 0.75 -12.5353
-2 0.75 -8.19302
-1.75 0.75 -1.85639
-1.5 0.75 10.4672
-1.25 0.75 42.7128
-1 0.75 122.477
-0.75 0.75 336.302
-0.5 0.75 1052.96
-0.25 0.75 3198.01
0 0.75 3372.36
0.25 0.75 3198.01
0.5 0.75 1052.96
0.75 0.75 336.301
1 0.75 122.475
1.25 0.75 42.7104
1.5 0.75 10.4648
1.75 0.75 -1.85915
2 0.75 -8.19592
2.25 0.75 -12.5388
2.5 0.75 -15.7768
2.75 0.75 -18.1191
3 0.75 -19.6913
3.25 0.75 -20.5316
3.5 0.75 -20.6203
3.75 0.75 -19.991
4 0.75 -18.6684
4.25 0.75 -16.6806
4.5 0.75 -14.0739
4.75 0.75 -10.904
5 0.75 -7.24377
5.25 0.75 -3.17647
5.5 0.75 1.20418
5.75 0.75 5.79908
6 0.75 10.5113
6.25 0.75 15.2555
6.5 0.75 19.9811
6.75 0.75 24.7232
7 0.75 29.7664
7.25 0.75 35.9284
7.5 0.75 45.7904
7.75 0.75 67.5843
8 0.75 49.6757
-8 1 50.6639
-7.75 1 68.5314
-7.5 1 45.5971
-7.25 1 35.1523
-7 1 28.632
-6.75 1 23.3348
-6.5 1 18.395
-6.25 1 13.498
-6 1 8.59186
-5.75 1 3.71581
-5.5 1 -1.05397
-5.25 1 -5.6273
-5 1 -9.91064
-4.75 1 -13.8143
-4.5 1 -17.2579
-4.25 1 -20.1693
-4 1 -22.492
-3.75 1 -24.1753
-3.5 1 -25.1828
-3.25 1 -25.4734
-3 1 -24.9818
-2.75 1 -23.6741
-2.5 1 -21.4015
-2.25 1 -17.7821
-2 1 -12.1512
-1.75 1 -2.75656
-1.5 1 14.6518
-1.25 1 50.5191
-1 1 131.565
-0.75 1 345.117
-0.5 1 1059.9
-0.25 1 3203.64
0 1 3377.83
0.25 1 3203.65
0.5 1 1059.9
0.75 1 345.115
1 1 131.564
1.25 1 50.5172
1.5 1 14.6496
1.75 1 -2.75902
2 1 -12.1539
2.25 1 -17.7854
2.5 1 -21.405
2.75 1 -23.6781
3 1 -24.9861
3.25 1 -25.478
3.5 1 -25.1876
3.75 1 -24.1801
4 1 -22.4967
4.25 1 -20.174
4.5 1 -17.2624
4.75 1 -13.8185
5 1 -9.91432
5.25 1 -5.63034
5.5 1 -1.05653
5.75 1 3.71403
6 1 8.59102
6.25 1 13.4979
6.5 1 18.3959
6.75 1 23.3367
7 1 28.6351
7.25 1 35.1571
7.5 1 45.6044
7.75 1 68.5438
8 1 50.6719
-8 1.25 51.3174
-7.75 1.25 69.3629
-7.5 1.25 45.4568
-7.25 1.25 34.4408
-7 1.25 27.512
-6.75 1.25 21.8823
-6.5 1.25 16.6537
-6.25 1.25 11.4921
-6 1.25 6.33623
-5.75 1.25 1.21921
-5.5 1.25 -3.78699
-5.25 1.25 -8.59521
-5 1.25 -13.1147
-4.75 1.25 -17.2581
-4.5 1.25 -20.9464
-4.25 1.25 -24.1099
-4 1.25 -26.6934
-3.75 1.25 -28.6475
-3.5 1.25 -29.9355
-3.25 1.25 -30.5137
-3 1.25 -30.3075
-2.75 1.25 -29.2648
-2.5 1.25 -27.1978
-2.25 1.25 -23.647
-2 1.25 -17.8619
-1.75 1.25 -8.08802
-1.5 1.25 9.40737
-1.25 1.25 43.5587
-1 1.25 118.623
-0.75 1.25 315.05
-0.5 1.25 972.254
-0.25 1.25 2944.29
0 1.25 3104.61
0.25 1.25 2944.29
0.5 1.25 972.252
0.75 1.25 315.049
1 1.25 118.622
1.25 1.25 43.5572
1.5 1.25 9.4056
1.75 1.25 -8.09007
2 1.25 -17.8643
2.25 1.25 -23.6499
2.5 1.25 -27.2009
2.75 1.25 -29.2685
3 1.25 -30.3117
3.25 1.25 -30.518
3.5 1.25 -29.9403
3.75 1.25 -28.6524
4 1.25 -26.6983
4.25 1.25 -24.1148
4.5 1.25 -20.9512
4.75 1.25 -17.2625
5 1.25 -13.1189
5.25 1.25 -8.59896
5.5 1.25 -3.79004
5.75 1.25 1.21679
6 1.25 6.33456
6.25 1.25 11.4913
6.5 1.25 16.6538
6.75 1.25 21.8834
7 1.25 27.5144
7.25 1.25 34.4446
7.5 1.25 45.463
7.75 1.25 69.3739
8 1.25 51.3245
-8 1.5 51.2722
-7.75 1.5 69.3806
-7.5 1.5 44.8177
-7.25 1.5 33.3384
-7 1.5 26.0324
-6.75 1.5 20.0701
-6.5 1.5 14.5394
-6.25 1.5 9.0976
-6 1.5 3.68028
-5.75 1.5 -1.68137
-5.5 1.5 -6.91641
-5.25 1.5 -11.9388
-5 1.5 -16.6587
-4.75 1.5 -20.9906
-4.5 1.5 -24.8586
-4.25 1.5 -28.1963
-4 1.5 -30.9547
-3.75 1.5 -33.0928
-3.5 1.5 -34.5847
-3.25 1.5 -35.4024
-3 1.5 -35.4942
-2.75 1.5 -34.8323
-2.5 1.5 -33.2706
-2.25 1.5 -30.4296
-2 1.5 -25.6859
-1.75 1.5 -17.5932
-1.5 1.5 -3.12652
-1.25 1.5 24.96
-1 1.5 86.4887
-0.75 1.5 247.128
-0.5 1.5 783.513
-0.25 1.5 2391.2
0 1.5 2522.36
0.25 1.5 2391.21
0.5 1.5 783.511
0.75 1.5 247.128
1 1.5 86.4884
1.25 1.5 24.959
1.5 1.5 -3.12774
1.75 1.5 -17.5947
2 1.5 -25.6879
2.25 1.5 -30.4323
2.5 1.5 -33.2736
2.75 1.5 -34.8358
3 1.5 -35.4981
3.25 1.5 -35.4066
3.5 1.5 -34.5893
3.75 1.5 -33.0976
4 1.5 -30.9597
4.25 1.5 -28.2014
4.5 1.5 -24.8636
4.75 1.5 -20.9955
5 1.5 -16.6633
5.25 1.5 -11.943
5.5 1.5 -6.92009
5.75 1.5 -1.6845
6 1.5 3.67791
6.25 1.5 9.09602
6.5 1.5 14.5387
6.75 1.5 20.0704
7 1.5 26.0338
7.25 1.5 33.3413
7.5 1.5 44.8228
7.75 1.5 69.39
8 1.5 51.2781
