LSDChannel Class Reference

This object inherets from LSDIndexChannel and is used for chi analysis. More...

#include <LSDChannel.hpp>

Inheritance diagram for LSDChannel:

Public Member Functions
	LSDChannel ()
	Defualt constructor. Just makes an empty channel. More...
	LSDChannel (LSDIndexChannel &InChann)
	Creates an LSDChannel by copying from an IndexChannel. More...
	LSDChannel (int StartNode, int EndNode, LSDFlowInfo &FlowInfo)
	Creates an index channel with just the node index of the starting and ending nodes. More...
	LSDChannel (int StartJunction, int StartNode, int EndJunction, int EndNode, LSDFlowInfo &FlowInfo)
	Creates an index channel with just the node index of the starting and ending nodes also includes junction information. More...
	LSDChannel (int StartNode, int EndNode, float downslope_chi, float m_over_n, float A_0, LSDFlowInfo &FlowInfo, LSDRaster &Elevation_Raster)
	This calculates all the channel areas, elevations and chi parameters based on for a starting node index and ending node index. More...
	LSDChannel (int StartNode, int EndNode, float downslope_chi, float m_over_n, float A_0, LSDFlowInfo &FlowInfo, LSDRaster &Elevation_Raster, LSDRaster &DA)
	This calculates all the channel areas, elevations and chi parameters based on for a starting node index and ending node index. More...
	LSDChannel (float downslope_chi, float m_over_n, float A_0, LSDIndexChannel &InChann, LSDFlowInfo &FlowInfo, LSDRaster &Elevation_Raster)
	This calculates all the channel areas, elevations and chi parameters based on for a given LSDChannelIndex. More...
LSDIndexRaster	print_channel_to_IndexRaster (LSDFlowInfo &FlowInfo)
	This function prints the channel to an LSDIndexRaster. More...
vector< float >	get_Chi ()
vector< float >	get_Elevation ()
void	calculate_chi (float downslope_chi, float m_over_n, float A_0, LSDFlowInfo &FlowInfo)
	This function uses a flow info object to calculate the chi values in the channel. More...
void	calculate_chi (float downslope_chi, float m_over_n, float A_0, LSDRaster &FlowAccum, LSDFlowInfo &FlowInfo)
	This function uses a flow info as well as a flow accumulation object. More...
float	retrieve_chi_at_channel_node (int ch_node)
	Get chi value at channel node. More...
void	retrieve_node_information (int ch_node, float &elev, float &chi, float &drainarea)
	Get node chi value, elevation and drainage area. More...
void	find_most_likeley_segments (int minimum_segment_length, float sigma, int target_nodes, vector< float > &b_vec, vector< float > &m_vec, vector< float > &r2_vec, vector< float > &DW_vec, vector< float > &thinned_chi, vector< float > &thinned_elev, vector< float > &fitted_elev, vector< int > &node_ref_thinned, vector< int > &these_segment_lengths, float &this_MLE, int &this_n_segments, int &n_data_nodes, float &this_AIC, float &this_AICc)
	This function looks for the most likeley segments. More...
void	find_best_fit_m_over_n_with_segments (int n_movern, float d_movern, float start_movern, float downslope_chi, float A_0, LSDFlowInfo &FlowInfo, int minimum_segment_length, float sigma, float target_nodes)
	This function looks for the best fit of a channel for a range of m_over_n values where the channel has segments. More...
void	find_best_fit_m_over_n_with_segments ()
	This function loops through m_over_n looking for best fit segments.
int	calculate_channel_heads (int min_seg_length_for_channel_heads, float A_0, float m_over_n, LSDFlowInfo &FlowInfo)
	This functions calculates channel heads based on chi segment fitting. More...
void	write_channel_to_csv (string path, string filename, LSDRaster &flow_dist)
	This function writes the channel to a csv file. More...
Public Member Functions inherited from LSDIndexChannel
	LSDIndexChannel ()
	The create function. This is default and throws an error.
	LSDIndexChannel (int StartNode, int EndNode, LSDFlowInfo &FlowInfo)
	Create LSDIndexChannel object between a start and end node. More...
	LSDIndexChannel (int StartJunction, int StartNode, int EndJunction, int EndNode, LSDFlowInfo &FlowInfo)
	Create LSDIndexChannel object between starting junction and node and ending junction and node. More...
	LSDIndexChannel (vector< float > &X_coords, vector< float > &Y_coords, LSDFlowInfo &FlowInfo, float threshold_area, float threshold_distance)
int	get_StartJunction () const
int	get_EndJunction () const
int	get_StartNode () const
int	get_EndNode () const
int	get_NRows () const
int	get_NCols () const
float	get_XMinimum () const
float	get_YMinimum () const
float	get_DataResolution () const
int	get_NoDataValue () const
map< string, string >	get_GeoReferencingStrings () const
vector< int >	get_RowSequence () const
vector< int >	get_ColSequence () const
vector< int >	get_NodeSequence () const
int	get_n_nodes_in_channel () const
void	get_row_column_of_end_node (LSDFlowInfo &FlowInfo, int &row, int &col)
	gets the row and column of the end node More...
int	get_node_in_channel (int n_node)
	This gets the node index at a given node in the index channel. More...
void	truncate_final_node ()
	This removes the final node in a channel. More...
int	get_contributing_pixels_at_node (int n_node, LSDFlowInfo &FlowInfo)
	Get the number of contributing pixels at a given node in the channel. More...
void	get_node_row_col_in_channel (int n_node, int &node, int &row, int &col)
	This gets the node, row, and column index. More...
int	get_contributing_pixels_at_outlet (LSDFlowInfo &FlowInfo)
	This gets the contriubting pixels at the outlet of the channel. More...
int	get_contributing_pixels_at_penultimate_node (LSDFlowInfo &FlowInfo)
	Gets the pixels at the penultimate node. More...
LSDIndexRaster	print_index_channel_to_index_raster ()
void	append_index_channel_to_index_raster (LSDIndexRaster &old_raster)
	This function appends a channel onto an existing LSDIndexRaster. More...
void	get_coordinates_of_channel_nodes (vector< double > &X_coordinates, vector< double > &Y_coordinates, LSDFlowInfo &FlowInfo)
	Function to get vectors with the X and Y coordinates of nodes in the channel. More...
void	get_coordinates_of_channel_nodes (vector< float > &X_coordinates, vector< float > &Y_coordinates)
	Function to get vectors with the X and Y coordinates of nodes in the channel. More...
void	write_channel_to_csv (string path, string filename)
	Function to get write index channel to csv. More...
void	write_channel_to_csv (string path, string filename, LSDFlowInfo &FlowInfo, LSDRaster &FlowDistance, LSDRaster &Elevation)
	Function to get write index channel to csv Similar to above but mimics code in other objects to ensure you get the same channels. More...

Protected Attributes
vector< float >	Elevation
	Elevation vector.
vector< float >	Chi
	Chi vector.
vector< float >	DrainageArea
	Drainage area vector.
Protected Attributes inherited from LSDIndexChannel
int	NRows
	Number of rows.
int	NCols
	Number of columns.
float	XMinimum
	Minimum X coordinate.
float	YMinimum
	Minimum Y coordinate.
float	DataResolution
	Data resolution.
int	NoDataValue
	No data value.
map< string, string >	GeoReferencingStrings
	A map of strings for holding georeferencing information.
int	StartJunction
	The starting junction (numbered within LSDJunctionNetwork object).
int	StartNode
	The node index of the starting Junction (numbered in the FlowInfo object).
int	EndJunction
	The ending junction (numbered within LSDJunctionNetwork object).
int	EndNode
	The node index of the ending Junction (numbered in the FlowInfo object).
vector< int >	RowSequence
	Vector of row indices.
vector< int >	ColSequence
	Vector of column indices.
vector< int >	NodeSequence
	Vector of node indices.

Detailed Description

This object inherets from LSDIndexChannel and is used for chi analysis.

Constructor & Destructor Documentation

LSDChannel::LSDChannel ( )

inline

Defualt constructor. Just makes an empty channel.

Author

SMM

Date

24/09/14

LSDChannel::LSDChannel ( LSDIndexChannel &  InChann )

inline

Creates an LSDChannel by copying from an IndexChannel.

The starting node is upstream and the ending node is downstream. In this create function the junction indices are left blank (this can describe a channel between two arbitraty points.

Parameters

InChann

LSDIndexChannel object.

Author

SMM

Date

01/01/12

LSDChannel::LSDChannel ( int  StartNode, int  EndNode, LSDFlowInfo &  FlowInfo  )

inline

Creates an index channel with just the node index of the starting and ending nodes.

The starting node is upstream and the ending node is downstream. In this create function the junction indices are left blank (this can describe a channel between two arbitraty points.

Parameters

StartNode	Starting node.
EndNode	Ending node.
FlowInfo	LSDFlowInfo object.

Author

SMM

Date

01/01/12

LSDChannel::LSDChannel ( int  StartJunction, int  StartNode, int  EndJunction, int  EndNode, LSDFlowInfo &  FlowInfo  )

inline

Creates an index channel with just the node index of the starting and ending nodes also includes junction information.

The starting node is upstream and the ending node is downstream. In this create function the junction indices are left blank (this can describe a channel between two arbitraty points.

Parameters

StartJunction	Starting junction.
StartNode	Starting node.
EndJunction	Ending junction.
EndNode	Ending node.
FlowInfo	LSDFlowInfo object.

Author

SMM

Date

01/01/12

LSDChannel::LSDChannel ( int  StartNode, int  EndNode, float  downslope_chi, float  m_over_n, float  A_0, LSDFlowInfo &  FlowInfo, LSDRaster &  Elevation_Raster  )

inline

This calculates all the channel areas, elevations and chi parameters based on for a starting node index and ending node index.

Parameters

StartNode	Starting node.
EndNode	Ending node.
downslope_chi	Downslope Chi value.
m_over_n	m over n ratio.
A_0	A_0 value.
FlowInfo	LSDFlowInfo object.
Elevation_Raster	Elevation LSDRaster object.

Author

SMM

Date

01/01/12

LSDChannel::LSDChannel ( int  StartNode, int  EndNode, float  downslope_chi, float  m_over_n, float  A_0, LSDFlowInfo &  FlowInfo, LSDRaster &  Elevation_Raster, LSDRaster &  DA  )

inline

This calculates all the channel areas, elevations and chi parameters based on for a starting node index and ending node index.

Parameters

StartNode	Starting node.
EndNode	Ending node.
downslope_chi	Downslope Chi value.
m_over_n	m over n ratio.
A_0	A_0 value.
FlowInfo	LSDFlowInfo object.
Elevation_Raster	Elevation LSDRaster object.
DA_raster	Drainage area raster LSDRaster object

Author

SMM

Date

01/01/12

LSDChannel::LSDChannel ( float  downslope_chi, float  m_over_n, float  A_0, LSDIndexChannel &  InChann, LSDFlowInfo &  FlowInfo, LSDRaster &  Elevation_Raster  )

inline

This calculates all the channel areas, elevations and chi parameters based on for a given LSDChannelIndex.

Parameters

downslope_chi	Downslope Chi value.
m_over_n	m over n ratio.
A_0	A_0 value.
InChann	LSDIndexChannel object.
FlowInfo	LSDFlowInfo object.
Elevation_Raster	Elevation LSDRaster object.

Author

SMM

Date

01/01/12

Member Function Documentation

int LSDChannel::calculate_channel_heads	(	int	min_seg_length_for_channel_heads,
		float	A_0,
		float	m_over_n,
		LSDFlowInfo &	FlowInfo
	)

This functions calculates channel heads based on chi segment fitting.

Parameters

min_seg_length_for_channel_heads
A_0
m_over_n
FlowInfo

Author

FC

Date

25/09/13

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Calculate channel head locations using chi segment fitting.

Fitting segments to the chi-elevation data of the main stem. We assume that the profile is made up of 2 segments in chi-space: a linear channel segment and a non-linear hillslope segment. We loop through the possible combinations of segment lengths, performing a linear regression to calculate the r^2 and DW of each segment length. We then calculate a test value: r^2 of the channel segment - ((DW of the hillslope segment - 2)/2). This value will vary between 0 and 1. The maximum test_value will give the best fit channel and hillslope segments. Need to get the best fit m_over_n value first. Parameters: min_seg_length_for_channel_heads (length used for fitting segments to the chi- elevation profile, a value of 10 is suggested), A_0, m over n, FlowInfo. Return value: integer with the node index of the channel head location. FC 25/09/2013

void LSDChannel::calculate_chi	(	float	downslope_chi,
		float	m_over_n,
		float	A_0,
		LSDFlowInfo &	FlowInfo
	)

This function uses a flow info object to calculate the chi values in the channel.

Parameters

downslope_chi	Downslope Chi value.
m_over_n	m over n ratio.
A_0	A_0 value.
FlowInfo	LSDFlowInfo object.

Author

SMM

Date

01/01/12

void LSDChannel::calculate_chi	(	float	downslope_chi,
		float	m_over_n,
		float	A_0,
		LSDRaster &	FlowAccum,
		LSDFlowInfo &	FlowInfo
	)

This function uses a flow info as well as a flow accumulation object.

to calculate the chi values in the channel.

Parameters

downslope_chi	Downslope Chi value.
m_over_n	m over n ratio.
A_0	A_0 value.
FlowAccum	a raster of flow acucmulation. Usually this will be a drainage area but in some cases it will be discharge so orographic effects can be determined
FlowInfo	LSDFlowInfo object.

Author

SMM

Date

24/09/14

void LSDChannel::find_best_fit_m_over_n_with_segments	(	int	n_movern,
		float	d_movern,
		float	start_movern,
		float	downslope_chi,
		float	A_0,
		LSDFlowInfo &	FlowInfo,
		int	minimum_segment_length,
		float	sigma,
		float	target_nodes
	)

This function looks for the best fit of a channel for a range of m_over_n values where the channel has segments.

Parameters

n_movern
d_movern
start_movern
downslope_chi	Downslope Chi value.
A_0	A_0 value.
FlowInfo	LSDFlowInfo object.
minimum_segment_length
sigma	Sigma value.
target_nodes

Author

SMM

Date

01/01/13

void LSDChannel::find_most_likeley_segments	(	int	minimum_segment_length,
		float	sigma,
		int	target_nodes,
		vector< float > &	b_vec,
		vector< float > &	m_vec,
		vector< float > &	r2_vec,
		vector< float > &	DW_vec,
		vector< float > &	thinned_chi,
		vector< float > &	thinned_elev,
		vector< float > &	fitted_elev,
		vector< int > &	node_ref_thinned,
		vector< int > &	these_segment_lengths,
		float &	this_MLE,
		int &	this_n_segments,
		int &	n_data_nodes,
		float &	this_AIC,
		float &	this_AICc
	)

This function looks for the most likeley segments.

Parameters

minimum_segment_length
sigma	Sigma value.
target_nodes
b_vec	Vector of b values.
m_vec	Vector of m values.
r2_vec	Vector of r-squared values.
DW_vec	Vector of Durbin-Watson values.
thinned_chi
thinned_elev
fitted_elev
node_ref_thinned
these_segment_lengths
this_MLE
this_n_segments
n_data_nodes
this_AIC
this_AICc

Author

SMM

Date

01/01/13

vector<float> LSDChannel::get_Chi ( )

inline

Returns

Vector of chi values.

vector<float> LSDChannel::get_Elevation ( )

inline

Returns

Vector of elevation values.

LSDIndexRaster LSDChannel::print_channel_to_IndexRaster

(

LSDFlowInfo &

FlowInfo

)

This function prints the channel to an LSDIndexRaster.

Returns

Index raster of channel nodes

Author

FJC

Date

21/08/15

float LSDChannel::retrieve_chi_at_channel_node ( int  ch_node )

inline

Get chi value at channel node.

Parameters

ch_node

Integer node index.

Returns

chi value at channel node.

Author

SMM

Date

01/01/12

void LSDChannel::retrieve_node_information ( int  ch_node, float &  elev, float &  chi, float &  drainarea  )

inline

Get node chi value, elevation and drainage area.

Parameters

ch_node	Integer node index.
elev	Elevation data.
chi	Chi Value
drainarea	Drainage area.

Author

SMM

Date

01/01/12

void LSDChannel::write_channel_to_csv	(	string	path,
		string	filename,
		LSDRaster &	flow_dist
	)

This function writes the channel to a csv file.

Parameters

filename

the filename of the channel (whithout the .csv)

Author

SMM

Date

24/09/14

---

The documentation for this class was generated from the following files:

• LSDChannel.hpp
• LSDChannel.cpp