[GRASS-SVN] r32154 - grass-addons/gipe/i.vi

[svn_grass at osgeo.org]

Author: ychemin
Date: 2008-07-18 03:08:52 -0400 (Fri, 18 Jul 2008)
New Revision: 32154

Added:
   grass-addons/gipe/i.vi/evi.c
Modified:
   grass-addons/gipe/i.vi/main.c
Log:
Added EVI

Added: grass-addons/gipe/i.vi/evi.c
===================================================================
--- grass-addons/gipe/i.vi/evi.c	                        (rev 0)
+++ grass-addons/gipe/i.vi/evi.c	2008-07-18 07:08:52 UTC (rev 32154)
@@ -0,0 +1,24 @@
+#include<stdio.h>
+#include<math.h>
+#include<stdlib.h>
+
+//EVI: Enhanced Vegetation Index
+//Huete A.R., Liu H.Q., Batchily K., vanLeeuwen W. (1997)
+//A comparison of vegetation indices global set of TM images for EOS-MODIS
+//Remote Sensing of Environment, 59:440-451.
+
+double e_vi( double bluechan, double redchan, double nirchan )
+{
+	double tmp, result;
+	
+	tmp = nirchan + 6.0*redchan - 7.5*bluechan + 1.0 ;
+
+	if( tmp ==  0.0 ){
+		result = -1.0;
+	} else {
+		result = 2.5 * ( nirchan - redchan ) / tmp ;
+	}
+	
+	return result;
+
+}

Modified: grass-addons/gipe/i.vi/main.c
===================================================================
--- grass-addons/gipe/i.vi/main.c	2008-07-17 23:00:26 UTC (rev 32153)
+++ grass-addons/gipe/i.vi/main.c	2008-07-18 07:08:52 UTC (rev 32154)
@@ -3,7 +3,7 @@
  * MODULE:       i.vi
  * AUTHOR(S):    Baburao Kamble baburaokamble at gmail.com
  *		 Yann Chemin - ychemin at gmail.com
- * PURPOSE:      Calculates 13 vegetation indices 
+ * PURPOSE:      Calculates 14 vegetation indices 
  * 		 based on biophysical parameters. 
  *
  * COPYRIGHT:    (C) 2002-2006 by the GRASS Development Team
@@ -17,8 +17,10 @@
  *               Those can be any use by standard satellite having V and IR.
  *		 However arvi uses red, nir and blue; 
  *		 GVI uses B,G,R,NIR, chan5 and chan 7 of landsat;
- *		 and GARI uses B,G,R and NIR.      
+ *		 and GARI uses B,G,R and NIR.   
  *
+ * Changelog:	 Added EVI on 20080718 (Yann)
+ *
  *****************************************************************************/
 
 #include <stdio.h>
@@ -31,6 +33,7 @@
 double nd_vi( double redchan, double nirchan );
 double ip_vi( double redchan, double nirchan );
 double d_vi( double redchan, double nirchan );
+double e_vi( double bluechan, double redchan, double nirchan );
 double p_vi( double redchan, double nirchan );
 double wd_vi( double redchan, double nirchan );
 double sa_vi( double redchan, double nirchan );
@@ -83,7 +86,7 @@
 
 	module = G_define_module();
 	module->keywords = _("vegetation index, biophysical parameters");
-	module->description = _("13 types of vegetation indices from red and nir, and only some requiring additional bands");
+	module->description = _("14 types of vegetation indices from red and nir, and only some requiring additional bands");
 
 	/* Define the different options */
 	input1 = G_define_option() ;
@@ -91,7 +94,7 @@
 	input1->type       = TYPE_STRING;
 	input1->required   = YES;
 	input1->gisprompt  =_("Name of VI");
-	input1->description=_("Name of VI: sr,ndvi,ipvi,dvi,pvi,wdvi,savi,msavi,msavi2,gemi,arvi,gvi,gari.");
+	input1->description=_("Name of VI: sr,ndvi,ipvi,dvi,evi,pvi,wdvi,savi,msavi,msavi2,gemi,arvi,gvi,gari.");
 	input1->answer     =_("ndvi");
 
 	input2 = G_define_option() ;
@@ -257,7 +260,6 @@
 		DCELL d_chan7chan;
 		G_percent(row,nrows,2);
 //		printf("row = %i/%i\n",row,nrows);
-		/* read soil input maps */	
 		if(G_get_raster_row(infd_redchan,inrast_redchan,row,data_type_redchan)<0)
 			G_fatal_error(_("Could not read from <%s>"),redchan);
 		if(G_get_raster_row(infd_nirchan,inrast_nirchan,row,data_type_nirchan)<0)
@@ -390,6 +392,11 @@
 					d =  d_vi(d_redchan,d_nirchan );
 					((DCELL *) outrast)[col] = d;
 				}
+				/*calculate evi	            */
+				if (!strcoll(viflag,"evi")){
+					d =  e_vi(d_bluechan,d_redchan,d_nirchan );
+					((DCELL *) outrast)[col] = d;
+				}
 				/*calculate pvi	            */
 				if (!strcoll(viflag,"pvi")){
 					d =  p_vi(d_redchan,d_nirchan );