Support added for diff, norm functions

1 files changed, 203 insertions, 0 deletions

diff --git a/src/c/differential_calculus/diff/i16diffca.c b/src/c/differential_calculus/diff/i16diffca.c
new file mode 100644
index 0000000..d1c70a5
--- /dev/null
+++ b/src/c/differential_calculus/diff/i16diffca.c
@@ -0,0 +1,203 @@
+/* Copyright (C) 2016 - IIT Bombay - FOSSEE
+
+ This file must be used under the terms of the CeCILL.
+ This source file is licensed as described in the file COPYING, which
+ you should have received as part of this distribution.  The terms
+ are also available at
+ http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
+ Author: Siddhesh Wani
+ Organization: FOSSEE, IIT Bombay
+ Email: toolbox@scilab.in
+*/
+
+ /* This function calculates difference between adjacent members of given 
+ input array/matrix */
+
+#include "diffc.h"
+
+
+void i16diffca(int16 *in, int row, int col, int depth, int dim, int16 *out)
+{
+	int counter, depth_count;
+	int row_count, col_count;
+	int16 *buffer; /*To store intermediate results*/
+
+	depth_count = 1;
+	
+	if(dim == 0)
+	{	/*For dim = 0, we calculate difference between adjacent elements 
+		in case of arrays. In case of matrices, we calculate difference along
+		first column, and then continue to second (diff between first element
+		of second column and last element of first column, then third etc.*/
+		if(depth == 1)
+		{/*for depth=1, a buffer is not needed. Directly write result in 
+			out buffer*/
+			for(counter = 0;  counter < row*col - depth_count; counter++)
+			{
+				out[counter] = in[counter+1] - in[counter];
+			}
+		}
+		else
+		{	/*define  buffer for storing intermediate results*/
+			
+			buffer = (int16 *) malloc (sizeof(int16)*(row*col-1));
+			
+			while(depth_count <= depth)
+			{
+				if(depth_count == 1)
+				{
+					/*calculate diff and store in buffer*/
+					for(counter = 0;  counter < row*col - depth_count; counter++)
+					{
+						buffer[counter] = in[counter+1] - in[counter];
+					}
+				}
+				else if(depth_count < depth)
+				{
+					for(counter = 0;  counter <= row*col - depth_count ; counter++)
+					{
+						buffer[counter] = buffer[counter+1] - buffer[counter];
+					}
+				}
+				/*For last step use output buffer to store result*/
+				else 
+				{
+					for(counter = 0;  counter < row*col - depth_count; counter++)
+					{
+						out[counter] = buffer[counter+1] - buffer[counter];
+					}
+				}
+				depth_count += 1;
+			}
+		}
+		
+	}
+	else if(dim == 1) 
+	{
+		/*For dim = 1, difference is calculated along rows. Each element of 
+		first row is subtracted from corresponding element of second row and
+		result is stored in first row. Same thing is repeated till last row. */
+
+		if (depth == 1)
+		{
+			/*If depth is 1, store result directly in out buffer*/
+			for(col_count = 0; col_count < col; col_count++)
+			{
+				for(row_count = 0; row_count < row - 1; row_count++)
+				{
+					out[col_count*(row-1)+row_count] = in[col_count*row + row_count+1] \
+										- in[col_count*row + row_count];
+				}
+			}
+		}
+		else
+		{
+			/*If depth is not 1, declare a buffer to store intermediate 
+			results. At last step store result into out buffer*/
+			buffer = (int16 *) malloc (sizeof(int16)*((row-1)*col));
+			
+			while(depth_count <= depth)
+			{
+				if(depth_count == 1)
+				{
+					/*For first step, use in buffer and store results in buffer*/
+					for(col_count = 0; col_count < col; col_count++)
+					{
+						for(row_count = 0; row_count < row - 1; row_count++)
+						{
+							buffer[col_count*row+row_count] = in[col_count*row + row_count + 1] \
+												- in[col_count*row + row_count];
+						}
+
+					}
+				}	
+				else if(depth_count < depth)
+				{
+					for(col_count = 0; col_count < col; col_count++)
+					{
+						for(row_count = 0; row_count < row - depth_count; row_count++)
+						{
+							buffer[col_count*row+row_count] = buffer[col_count*row + row_count + 1] \
+												- buffer[col_count*row + row_count];
+						}
+
+					}
+				}
+				else
+				{
+					for(col_count = 0; col_count < col; col_count++)
+					{
+						for(row_count = 0; row_count < row - depth_count; row_count++)
+						{
+							out[col_count*(row-depth_count)+row_count] = buffer[col_count*row + row_count+1] \
+												- buffer[col_count*row + row_count];
+						}
+					}
+				}
+				depth_count +=1;
+			}
+		}
+	}
+	else if(dim == 2) 
+	{
+		/*For dim = 2, difference is calculated along columns. Each element of 
+		first column is subtracted from corresponding element of second column
+		and result is stored in first column. Same thing is repeated till last 
+		column. */
+		if(depth == 1)
+		{
+			for(row_count = 0; row_count < row; row_count++)
+			{
+				for(col_count = 0; col_count < col - 1; col_count++)
+				{
+					out[col_count*row+row_count] = in[(col_count+1)*row + row_count] \
+										- in[col_count*row + row_count];
+				}
+			}
+		}
+		else
+		{
+			/*If depth is not 1, declare a buffer to store intermediate 
+			results. At last step store result into out buffer*/
+			buffer = (int16 *) malloc (sizeof(int16)*(row*(col-1)));
+			
+			while(depth_count <= depth)
+			{
+				if(depth_count == 1)
+				{
+					for(row_count = 0; row_count < row; row_count++)
+					{
+						for(col_count = 0; col_count < col - 1; col_count++)
+						{
+							buffer[col_count*row+row_count] = in[(col_count+1)*row + row_count] \
+												- in[col_count*row + row_count];
+						}
+					}	
+				}
+				else if(depth_count < depth)
+				{
+					for(row_count = 0; row_count < row; row_count++)
+					{
+						for(col_count = 0; col_count < col - depth_count; col_count++)
+						{
+							buffer[col_count*row+row_count] = buffer[(col_count+1)*row + row_count] \
+												- buffer[col_count*row + row_count];
+						}
+					}
+				}
+				else
+				{
+					for(row_count = 0; row_count < row; row_count++)
+					{
+						for(col_count = 0; col_count < col - depth_count; col_count++)
+						{
+							out[col_count*row+row_count] = buffer[(col_count+1)*row + row_count] \
+												- buffer[col_count*row + row_count];
+						}
+					}
+				}
+				depth_count += 1;
+			}
+		}
+	}
+}