Step-by-step guide

Magics is internally working in cm. All the superpage, page and subpage dimension should be given in cm.  When working with png, you can set the parameter output_width to the number of pixel you want.  Magics will map this width with super_page_x_length to define a ratio and compute the height in pixel.

In the following example : we set the output_width to 1200, the page is the default A4 landscape. 1200 will match 29.7, the height will be computed to respect the aspect ratio ie, the height will be 848.

Python Example : resize a png
from Magics.macro import *
#Setting output
output = output(
    output_formats                = ['png'],
	output_name                   = 'size',
    output_name_first_page_number = 'off',
	output_width = 1200)
#Setting the coastlines
background = mcoast(
    map_coastline_land_shade        = 'on',
    map_coastline_land_shade_colour = 'cream')
#Setting data
grib = mgrib(grib_input_file_name = "path/data.grib")
#Defining the contour
contour = mcont(
plot(output, background, grib, data)