# Documentation

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# mfwdtran

Project geographic features to map coordinates

## Syntax

[x,y] = mfwdtran(lat,lon)
[x,y,z] = mfwdtran(lat,lon,alt)
[...] = mfwdtran(mstruct,...)

## Description

[x,y] = mfwdtran(lat,lon) applies the forward transformation defined by the map projection in the current map axes. You can use this function to convert point locations and line and polygon vertices given in latitudes and longitudes to a planar, projected map coordinate system.

[x,y,z] = mfwdtran(lat,lon,alt) applies the forward projection to 3-D input, resulting in 3-D output. If the input alt is empty or omitted, then alt = 0 is assumed.

[...] = mfwdtran(mstruct,...) requires a valid map projection structure as the first argument. In this case, no map axes is needed.

## Examples

collapse all

Get geographic location data for District of Columbia.

dc = shaperead('usastatelo', 'UseGeoCoords', true,...
'Selector',{@(name) strcmpi(name,'District of Columbia'),...
'Name'});
lat = [dc.Lat]';
lon = [dc.Lon]';
[lat lon]
ans =

38.9000  -77.0700
38.9500  -77.1200
39.0000  -77.0300
38.9000  -76.9000
38.7800  -77.0300
38.8000  -77.0200
38.8700  -77.0200
38.9000  -77.0700
38.9000  -77.0700
NaN       NaN

Obtain the UTM zone for this point.

dczone = utmzone(mean(lat,'omitnan'),mean(lon,'omitnan'))
dczone =

18S

Set up the UTM coordinate system based on this information.

utmstruct = defaultm('utm');
utmstruct.zone = dczone;
utmstruct.geoid = wgs84Ellipsoid;
utmstruct = defaultm(utmstruct)
utmstruct =

struct with fields:

mapprojection: 'utm'
zone: '18S'
angleunits: 'degrees'
aspect: 'normal'
falsenorthing: 0
falseeasting: 500000
fixedorient: []
geoid: [1×1 referenceEllipsoid]
maplatlimit: [32 40]
maplonlimit: [-78 -72]
mapparallels: []
nparallels: 0
origin: [0 -75 0]
scalefactor: 0.9996
trimlat: [-80 84]
trimlon: [-180 180]
frame: 'off'
ffill: 100
fedgecolor: [0.1500 0.1500 0.1500]
ffacecolor: 'none'
flatlimit: [32 40]
flinewidth: 2
flonlimit: [-3 3]
grid: 'off'
galtitude: Inf
gcolor: [0.1500 0.1500 0.1500]
glinestyle: ':'
glinewidth: 0.5000
mlineexception: []
mlinefill: 100
mlinelimit: []
mlinelocation: 1
mlinevisible: 'on'
plineexception: []
plinefill: 100
plinelimit: []
plinelocation: 1
plinevisible: 'on'
fontangle: 'normal'
fontcolor: [0.1500 0.1500 0.1500]
fontname: 'Helvetica'
fontsize: 10
fontunits: 'points'
fontweight: 'normal'
labelformat: 'compass'
labelrotation: 'off'
labelunits: 'degrees'
meridianlabel: 'off'
mlabellocation: 1
mlabelparallel: 40
mlabelround: 0
parallellabel: 'off'
plabellocation: 1
plabelmeridian: -78
plabelround: 0

Project the District of Columbia data from geographic coordinates into map coordinates for UTM zone 18S.

[x,y] = mfwdtran(utmstruct,lat,lon)
x =

1.0e+05 *

3.2049
3.1629
3.2421
3.3524
3.2367
3.2459
3.2476
3.2049
3.2049
NaN

y =

1.0e+06 *

4.3077
4.3134
4.3187
4.3074
4.2943
4.2965
4.3043
4.3077
4.3077
NaN

## See Also

#### Introduced before R2006a

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