[Plplot-general] plotting date time axis

[Pedro V. <ped...@sp...>]

Hi all

I am trying to do a plot where the X axis has a date format.

I'm following the example x29.cc , but I am having some trouble figuring it 
out


this is my code


this example plots 19 points, between these 2 dates

pls->ctime(2016, 5, 30, 0, 0, 0, tstart);
pls->ctime(2016, 6, 1, 0, 0, 0, tend);


that is, 2016-05-30 and 2016-06-01

for the example, I calculate the time interval for the 19 points as

time_t tinterval = (tend - tstart) / NSIZE;

then the x points are made this way, the start time plus the interval

for (int idx_orb = 0; idx_orb < NSIZE; idx_orb++)
{
x[idx_orb] = tstart + tinterval;
}


the plot is made in

pls->env(tstart, tend, 0, NSIZE, 0, 0);
pls->line(NSIZE, x, y);


however I don't get a date axis

the complete code:
thanks


pls->init();
pls->adv(0);
pls->scol0(0, 255, 255, 255);
pls->clear();
pls->scol0(1, 0, 0, 0);
pls->col0(1);

//data
const int NSIZE = 19;
PLFLT *x, *y;
x = new PLFLT[NSIZE];
y = new PLFLT[NSIZE];

//time
PLFLT tstart, tend;
pls->timefmt("%Y-%m-%d");
pls->ctime(2016, 5, 30, 0, 0, 0, tstart);
pls->ctime(2016, 6, 1, 0, 0, 0, tend);
time_t tinterval = (tend - tstart) / NSIZE;

for (int idx_orb = 0; idx_orb < NSIZE; idx_orb++)
{
x[idx_orb] = tstart + tinterval;
y[idx_orb] = idx_orb;
}

pls->env(tstart, tend, 0, NSIZE, 0, 0);
pls->line(NSIZE, x, y);
delete[] x;
delete[] y;