Binary grid data for splot command in gnuplot

Question

This question is with reference to the splot command of the popular plotting program gnuplot. When I wan plot the so-called grided data from a datafile, we separate the rows by a blank record such as the datafile shown below

0 1 2
1 2 3
2 3 4

0 1 -2
1 2 -3
2 3 -4

0 1 1.5
1 2 -1.2
2 3 4

How to do the same with binary datafile? In binary datafile, we simply store the records and we simply read the records sequentially as shown below

splot <file> binary format="%double%double%double" u 1:2:3

In this case, the data is read as un-gridded. How do I convert these data to grided data without using the gnuplot's dgrid3d command. I don't wan to use the dgrid3d command as it unnecessarily tries to construct grided data from the already grided data, which is time consuming.

Any help will be welcome.

Madhurjya

Answer 1

First, the data in your question is not "so-called grided data" because it represents just three repetitions of the three points (0,1), (1,2), and (2,3). Presumably, the data you intend is the following data or something similar.

0 1 2
0 2 3
0 3 4

1 1 -2
1 2 -3
1 3 -4

2 1 1.5
2 2 -1.2
2 3 4

Assume that these nine (x,y,z) triplets are sequentially written out to a file as a flat binary where the individual numbers are of type 'double'. In that case, the binary keyword would need to be followed by the record keyword to tell the splot command that the file has a 3x3 grid structure.

splot "test.bin" binary record=(3,3) format ="%double%double%double"