function plotly(x,y)
//if the file plotly.html already exists, delete it
if getos() == 'Windows' then unix('del plotly.html');
else unix('rm -f plotly.html'); end
header='';
container='';
js='';
write('plotly.html', [header;container;js])
if getos() == 'Windows' then winopen('plotly.html') end
endfunction
x=[0:0.1:2*%pi];
y=sin(x);
plotly(x,y)