Plotting Lines
Line plotting functionality covers many configurations from simplest case of plotting a single vector to displaying multiple lines at once with custom line specifictions.
gnuplot.plot(x)
Plot vector x using dots of first default Gnuplot type.
x=torch.linspace(-2*math.pi,2*math.pi)
gnuplot.plot(torch.sin(x))

In more general form, plot vector y vs x using the format
specified. The possible entries of format string can be:
* . for dots
* + for points
* - for lines
* +- for points and lines
* ~ for using smoothed lines with cubic interpolation
* | for using boxes
* v for drawing vector fiels. (In this case, x and y have to be two column vectors (x, xdelta), (y, ydelta))
* custom string, one can also pass custom strings to use full capability of gnuplot.
x = torch.linspace(-2*math.pi,2*math.pi)
gnuplot.plot('Sin',x/math.pi,torch.sin(x),'|')

To plot multiple curves at a time, one can pass each plot struct in a table.
x = torch.linspace(-2*math.pi,2*math.pi)
gnuplot.plot({'Cos',x/math.pi,torch.cos(x),'~'},{'Sin',x/math.pi,torch.sin(x),'|'})

One can pass data with multiple columns and use custom gnuplot style strings too. When multi-column data
is used, the first column is assumed to be the x values and the rest of the columns are separate y series.
x = torch.linspace(-5,5)
y = torch.sin(x)
yp = y+0.3+torch.rand(x:size())*0.1
ym = y-(torch.rand(x:size())*0.1+0.3)
yy = torch.cat(x,ym,2)
yy = torch.cat(yy,yp,2)
gnuplot.plot({yy,' filledcurves'},{x,yp,'lines ls 1'},{x,ym,'lines ls 1'},{x,y,'lines ls 1'})
