# Difference between revisions of "R.sun"

From GRASS-Wiki

HamishBowman (talk | contribs) (→Testing: addon template) |
HamishBowman (talk | contribs) (→Time step: +pics) |
||

Line 14: | Line 14: | ||

=== Time step === | === Time step === | ||

− | The following three images demonstrate the effects of using different ''step'' parameters. | + | The following three images demonstrate the effects of using different time '''step''' parameters. |

+ | r.sun -s elevin="gauss" glob_rad="rad.global.30minT" day=180 | ||

+ | |||

+ | [[File:Gauss_30min.png|400px|thumb|center|Default 30 minute time step over a Gaussian mound.]] | ||

− | |||

r.sun -s elevin="gauss" glob_rad="rad.global.15minT" day=180 | r.sun -s elevin="gauss" glob_rad="rad.global.15minT" day=180 | ||

+ | |||

+ | [[File:Gauss_15min.png|400px|thumb|center|15 minute time step over a Gaussian mound.]] | ||

+ | |||

r.sun -s elevin="gauss" glob_rad="rad.global.03minT" day=180 | r.sun -s elevin="gauss" glob_rad="rad.global.03minT" day=180 | ||

+ | [[File:Gauss_03min.png|400px|thumb|center|3 minute time step over a Gaussian mound.]] | ||

− | |||

− | |||

− | |||

− | |||

The 3 minute time step takes roughly ten times as long to run as the 30 minute timestep. | The 3 minute time step takes roughly ten times as long to run as the 30 minute timestep. |

## Revision as of 01:54, 19 May 2009

# r.sun

## Help page

- r.sun manual page

## Tips

### Testing

Create an artificial surface containing a Gaussian mound:

```
r.surf.volcano out=gauss method=gaussian kurtosis=1
```

### Time step

The following three images demonstrate the effects of using different time **step** parameters.

r.sun -s elevin="gauss" glob_rad="rad.global.30minT" day=180

r.sun -s elevin="gauss" glob_rad="rad.global.15minT" day=180

r.sun -s elevin="gauss" glob_rad="rad.global.03minT" day=180

The 3 minute time step takes roughly ten times as long to run as the 30 minute timestep.