Plotting a 3D curve from data file

Question

I have data file in the following format:

1,00000 2,00000 3,00000
1,37864 1,83839 2,90917
1,71932 1,75834 2,77034
2,03327 1,75821 2,58788
2,32958 1,83535 2,36475
2,61380 1,98720 2,10290
2,88682 2,21109 1,80385
3,14388 2,50283 1,46933
3,37385 2,85424 1,10207
3,55891 3,25003 0,70675
3,67565 3,66464 0,29077
3,69810 4,06096 -0,13516
3,60327 4,39280 -0,55697
3,37826 4,61289 -0,95808
3,02656 4,68499 -1,32117
2,57023 4,59570 -1,63053
2,04607 4,35956 -1,87439
1,49686 4,01436 -2,04634
0,96171 3,60912 -2,14556
0,46928 3,19100 -2,17583
...

That is, there is a 3-dimensional point on each line.

I want to plot these points as a curve in 3D space, so these points would be connected one by one starting from the first with straight lines.

However, the following gnuplot program does not work:

set xrange [-5:5]
set yrange [-5:5]
set ticslevel 0
splot "data.dat" u 1:2:3 with lines

It gives very strange results:

Looks like that gnuplot for some reason approximates all my data with integral points.

I thought that it may be that my data really gives this picture, however, when I asked gnuplot to plot only dots instead of lines, it still plotted only integral points, joints of the lines on the plot above.

Why is this so? I couldn't force google to give me an answer. Looks like no one interested in plotting curves in 3D space :)

Answer 1

You should replace coma with a dot in the data.dat file. Decimal separator is a subject of regional settings in most of operating systems. For example it's coma for region Russia and dot for US and UK.

On Linux regional settings can be checked with locale utility

locale -k LC_NUMERIC
decimal_point="."
thousands_sep=","
grouping=3;3
numeric-decimal-point-wc=46
numeric-thousands-sep-wc=44
numeric-codeset="UTF-8"

One of possibilities for conversion on Unix-like systems is to use sed for modifying file in place

sed -i "s/,/./g" data.dat