[Qgis-user] getting statistics from a raster layer

[Antonio Silva]

Hi fellows

This is my first post in this list. I've been using QGIS since the end of
last year. I run QGIS on a UBUNTU 12.04 64 bits system.

My purpose is to visualize and analyze fishery and oceanography information
on a GIS platform. I'm biologist / oceanographer and I work at Sao Paulo
Fisheries Institute, Brazil.

Well, I'd like to calculate some basic statistics (mean, median, maximum,
minimum, sd) from a raster layer.

At http://poet.jpl.nasa.gov/ I got the mean sea surface temperature off
southwestern Brazilian coast for some months. I downloaded the data in ARC
GRID ASCII format. They can be visualized easily on QGIS as a raster layer.
I also have a shape with a polygon that delimitates my area of interest.
I'd like to calculate the mean, max, min, etc. temperatures for this
specific area.

I learned to do this procedure in gvSIG (in Spanish, sorry):
SEXTANTE > HERRAMIENTAS BÁSICAS PARA CAPAS RASTER > CORTAR CAPA RASTER COM
CAPA DE POLÍGONOS
SEXTANTE > HERRAMIENTAS BÁSICAS PARA CAPAS RASTER > ESTADÍSDICAS BÁSICAS

However I did not find a way to do these calculations in QGIS.

Thanks in advance for any guidance.

All the best,

Antonio Olinto
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20120914/0eace8dd/attachment.html>