Matrix datasets - reading in and analysing

ROOT
1

dear Root gurus,

I have 2 ascii datasets presented in matrix format (originally 123 rows x 166 cols) but in this example presented as 8x6 matrix

dataset_1:

10.1190	10.0400	9.9540	9.8370	9.9470	10.3450
10.1050	10.0790	10.1180	9.9790	10.1080	10.5790
10.2910	10.2780	10.3500	10.3090	10.4560	10.8390
10.1850	10.2240	10.4300	10.6320	10.8470	11.0820
9.8930	10.0090	10.4130	10.9460	11.2660	11.3160
10.2140	10.2570	10.5180	11.1290	11.5250	11.6490
10.7170	10.7210	10.8510	11.4280	11.8120	11.9510
11.4870	11.5000	11.5190	11.8980	12.1400	12.2090

dataset_2:

10.1490	10.2010	10.2130	10.0590	10.0650	10.2720
10.3260	10.3360	10.2980	10.1630	10.2020	10.4620
10.5560	10.4640	10.2770	10.3860	10.5240	10.7000
10.3220	10.3600	10.4780	10.6570	10.8150	10.9480
9.7900	10.1120	10.8240	10.9600	11.0870	11.2040
10.1220	10.2910	10.7340	11.3290	11.6890	11.7490
10.6810	10.7520	10.9790	11.7260	12.1560	12.1850
11.5740	11.6290	11.7200	12.1650	12.4260	12.4550

I want to read them imultaneosly into either an Ntuple or TTree so that I can carry out aritmetic operations on both to generate some plots,

There are no explicit examples in the tutorials. To define the matrix and fill I’ve used

TMatrixF var(n,m); TNtutple *ntuple = new TNtuple("id","title","var"); ntuple->ReadFile(dataset)
It seems to work fine, but when I try to plot I get the error message:

Error: Can't call TNtuple::Plot("var") in current scope (tmpfile)(1) possible candidates are... (in TNtuple) (in TTree) *** Interpreter error recorvered ****

How can I solve this? :confused:

Secondly, the datasets come with an identical predefined grid to define the axis, i.e.

col- m -1.84 -1.59 -1.34 -1.09 -0.84 -0.59 row-n 7.9 7.65 7.4 7.15 6.9 6.65 6.4 6.15

what I’m doing wrong? Could someone please point me in the right direction?

Thanks!

2

Error: Can't call TNtuple::Plot("var") in current scope (tmpfile)(1) The error message is accurate, there is no method named Plot in the TNtuple class. You probably meant to use the Draw method.

Cheers,
Philippe.

3

[quote=“pcanal”]Error: Can't call TNtuple::Plot("var") in current scope (tmpfile)(1) The error message is accurate, there is no method named Plot in the TNtuple class. You probably meant to use the Draw method.
[/quote]

…Oops! sorry, yes I meant to use Draw instead. thanks. I’ve noticed that only the first column was filled in. I correctly defined the matrix precision and type so I’m not sure what the problem is?

cheers

4

TNtutple *ntuple = new TNtuple("id","title","var");explicit build a TNtuple with one column.

You may want to use a TTree and TTree::ReadFile instead.

Cheers,
Philippe.