4. Sub Function Descriptions: pixInstPrepXYZ

• pixInstPrepXYZ

  • Description:

  This function constructs XYZ vectors and matrices for pixel instruments specfied in a pixInst structure. The vectors and matrices are of the correct size for the function imageRectifier. The format of the input structure is described below. Note: if the z coordinate is not known, pixInst.z can be left empty.

  • Input:

Variable	Description
pixInst	Stucture where each entry is a type of pixel instruments. Field Entries are entered below depending on what is entered for the field ‘type.’
type	Descriptor of instrument type. Can either be ‘grid’,’xtransect’, or ’ytransect.’ For each type, input is defined below.
Grid- Good for bathymetric inversion algorithms and reduced resolution geo-rectified images
type	String of ‘Grid’
dx	Single Value of uniform grid resolution in world/local units
dy
xlim	[1 x 2] vector of minimum grid extents in world/local units
ylim
z	Elevation of instrument. Leave empty if not known. If entered here it is assumed constant across domain and in time.
yTransect- Good for alongshore current estimations or other alongshore variations in time.
type	String of ‘yTransect’
x	Single value X coordinate of transect, for points along transect this value is constant.
ylim	[1 x 2] vector of alongshore transect extents in world/local units
dy	Single Value of uniform transect resolution in world/local units
z	Elevation of instrument. Leave empty if not known. If entered here it is assumed constant across domain and in time
xTransect- Good for observing run-up and other cross shore variations in time.
type	String of ‘xTransect’
y	Single value Y coordinate of transect, for points along transect this value is constant.
xlim	[1 x 2] vector of cross-shore transect extents in world/local units
dz	Single Value of uniform transect resolution in world/local units
z	Elevation of instrument. Leave empty if not known. If entered here it is assumed constant across domain and in time

• Output:

Variable	Description
pixInst	Stucture where each entry is a type of pixel instruments. Each ‘type’ will have the same fields but different vector/matrix sizes as indicated in each column. N is number of points in Y Direction, M is number of points in X direction (Number of points as specified by limits and resolution).
field	grid	yTransect	xTransect
type	String of instrument description
	'grid'	'yTransect'	'xTransect'
dx	X resolution
	[1x1]	[]	[1x1]
dy	Y resolution
	[1x1]	[1x1]	[]
xlim	X limits
	[1x2]	[]	[1x2]
ylim	Y limits
	[1x2]	[1x2]	[]
z	Input Elevation of Instrument
y	Input Y coordinate of Instrument
	[]	[1x1]	[]
x	Input X coordinate of Instrument
	[]	[]	[1x1]
X	Instrument X Coordinates
	[NxM]	[Nx1]	[Mx1]
Y	Instrument Y Coordinates
	[NxM]	[Nx1]	[Mx1]
Z	Instrument Z Coordinates
	[NxM]	[Nx1]	[Mx1]
lrgb	Empty matrix of nans
	[NxMx3x1]	[Nx1x3]	[Mx1x3]
lgray	Empty matrix of nans
	[NxMx1]	[Nx1]	[Mx1]

• Required Core Sub-Functions:

  None.