mars bin

From DavinciWiki

Contents: Description, Arguments, Usage, Examples, Images, Sub-Functions, Related Functions, Source

Description

Map data in a vanilla file that have both latitude, longitude and a value for each point at a specified number of pixels per degree.

Arguments and Return Values

Arguments: Latitude and Longitude range, desired resolution, the data and an option to qurey for the data.

Return Value: An image of the specified latitude and longitude range at the specifed resolution and a map of the number of data points used for every specific point on the map

Usage

Syntax: mars_bin(upper lon, lower lon, upper lat, lower lat, resolution, vanilla file [, field] [, vanilla select] [, nofile = BOOL] [,null = VAL] [,polar = BOOL] [,east = BOOL])

'upper lon' - Upper Longitude

'lower lon' - Lower Longitude

'upper lat' - Upper Latitude

'lower lat' - Lower Latitude

'resolution' - Resolution in Pixels per Degree

'vanilla file' - Vanilla filename or data directory (VAR data if nofile is 1)

'field' - Binned field string if directory is specified

'vanilla select' - Vanilla select string if directory is specified

'nofile' - Use an array instead of a file for source data (lon, lat, value) format

'null' - Ignore value

'polar' - Works only for North Pole, use absolute value for South Pole. Takes only minlat, resolution and file

'east' - return the data in east positive coordinates

Examples

Using mars_bin with a data directory and field string

dv> a=mars_bin(360,0,90,-90,1,"/tes/mapping/data/p16139/","brightness_temp_bol","incidence 93 180 emission 0 30 brightness_temp_bol 100 270")
Apparent file size: 3x67926x1
Read ASCII file: 3x67926x1
Division by zero, 61270 times
struct, 2 elements
    cube: 360x180x1 array of double, bsq format [518,400 bytes]
    nobs: 360x180x1 array of float, bsq format [259,200 bytes]

Using mars_bin with a davinci array that has 3 columns longitude, latitude and value.

dv> a=ascii("ti_map.ascii",format=float)
Apparent file size: 3x338122x1
Read ASCII file: 3x338122x1
3x338122x1 array of float, bsq format [4,057,464 bytes]

dv> b=mars_bin(360,0,90,-90,2,a,nofile=1)
Division by zero, 112531 times
struct, 2 elements
   cube: 720x360x1 array of double, bsq format [2,073,600 bytes]
   nobs: 720x360x1 array of float, bsq format [1,036,800 bytes]

Next is a polar example

dv> data=ascii("NCR10-25.ascii")
Apparent file size: 3x195767x1
Read ASCII file: 3x195767x1
3x195767x1 array of int, bsq format [2,349,204 bytes]

If the data are centered on the south pole than use abs to trick mars_bin

dv> data[2]=abs(data[2])
1x195767x1 array of int, bsq format [783,068 bytes]

dv> c=mars_bin(75,4,data,nofile=1,polar=1)
Division by zero, 3323 times
struct, 2 elements
   cube: 120x120x1 array of double, bsq format [115,200 bytes]
   nobs: 120x120x1 array of float, bsq format [57,600 bytes]

Images

This is the output of the first example with the data on the left and the number of observations on the right.