interpxyz2grid#

[xgrid, ygrid, zgrid] = interpxyz2grid(x, y, z, gridsize, gridsizetype, xmin, xmax, ymin, ymax, zmin, zmax, RetainRatio, interpMethod, dispout)

Description#

Interpolate x (longitude), y (latitude) and z (elevation) data into a defined mesh

Inputs#

x

x (longitude) data extracted from xyz file

y

y (latitude) data extracted from xyz file

z

z (elevation) data extracted from xyz file

gridsize=100;
Grid size in x (longitude) and y (latitude) directions to interpolate elevation data on them
if gridsizetype=’length’ then gridsize is a distance between grid points
if gridsizetype=’points’ then gridsize is number of grid points in each direction
gridsizetype=’points’;
Grid size type
‘points’: gridsize is considered as number of grid points in each direction
‘length’: gridsize is considered as length between grid points
xmin=nanmin(x);

Minimum x (longitude) of domain to be interpolated

xmax=nanmax(x);

Maximum x (longitude) of domain to be interpolated

ymin=nanmin(y);

Minimum y (latitude) of domain to be interpolated

ymax=nanmax(y);

Maximum y (latitude) of domain to be interpolated

zmin=nanmin(z);
Minimum z (elevation) of domain to be interpolated
All z<zmin would be set to zmin
zmax=nanmax(z);
Maximum z (elevation) of domain to be interpolated
All z>zmax would be set to zmax
RetainRatio=’all’;
Define to down sample input data or not
‘all’: data are not down sampled
value between 0 and 1: percentage of retaining data
RetainRatio=0.8; : 80% of data are retained
interpMethod=’nearest’;
Interpolation method
‘linear’: Use default or ‘linear’ method to interpolate
‘nearest’: Use nearest neighbor method to interpolate
dispout=’no’;

Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs#

xgrid

Interpolated x (longitude) data on defined mesh

ygrid

Interpolated y (latitude) data on defined mesh

zgrid

Interpolated z (elevation) data on defined mesh

Examples#

x(:,1)=10.*rand(1000,1);
y(:,1)=10.*rand(1000,1);
z=x.^2+y.^2;
[xgrid,ygrid,zgrid]=interpxyz2grid(x,y,z,100,'points',nanmin(x),nanmax(x),nanmin(y),nanmax(y),nanmin(z),nanmax(z),'all','nearest','yes');

x(:,1)=(-90-(-91)).*rand(1000,1)+(-91);
y(:,1)=(31-(30)).*rand(1000,1)+(30);
z=x.^2+y.^2;
[xgrid,ygrid,zgrid]=interpxyz2grid(x,y,z,0.005,'length',nanmin(x),nanmax(x),nanmin(y),nanmax(y),nanmin(z),nanmax(z),'all','linear','yes');

References#

Geospatial data