Error while using the circlem function

I am trying to draw a circle on a map using the circlem function, but I am getting the following error:

??? Undefined function or method 'earthRadius' for input arguments of type 'char'.

Error in ==> circlem at 95 [circlelat,circlelon] = scircle1(lat,lon,radius,[],earthRadius(units));

Error in ==> mapexample at 8 q = circlem(24.65,25.91,150, 'facecolor', 'red')

Kindly help me resolve the issue.

Answer 1

[Geoff Hayes]

Ojaswita - the circlem function (Chad Greene's FEX submission found here) makes use of the Mapping Toolbox which the earthRadius function is a part of. The error message

 ??? Undefined function or method 'earthRadius' for input arguments of type 'char'.

is telling you that either you don't have this function or it is not within the MATLAB search path. At the very least, you will need this toolbox, so in the Command Window, type

 ver

to see your version of MATLAB and all installed products. Do you see the Mapping Toolbox in this list? If not, then you will need to purchase this software or find an alternative to the earthRadius function.

[Ojaswita]

Thanks for the reply. I downloaded the circlem function from the file exchange and added it using pathtool. I do have the mapping toolbox.

I tried to search for the earthRadius function in the file exchange, but did not find it.

[Chad Greene]

Yes indeed, this is strange. I can tell you have a license for the Mapping Toolbox, because circlem got past the license check assertion. Is it possible that you have a license for the Mapping Toolbox, but you didn't install it? If

which earthRadius

does not find anything, you can simply replace earthRadius(units) on line 95 with Earth's radius in whatever units you're using.

[Ojaswita]

Thanks... Yes, earyhRadius does not find anything. I replaced the value of the earth radius. And when I run my code, i get the following output on the command window (and no changes on the map)

q =

   Empty matrix: 0-by-1

Where q was my circlem function, which was written as:

q = circlem(24.65,25.91,150, 'facecolor', 'red')

What is going wrong... :( :(

[Geoff Hayes]

What are you replacing the earthRadius with? Have you tried stepping through the code (using the debugger) to figure out what is happening?

[Ojaswita]

I am replacing it with the radius of the earth = 6371000. I cant find the error in my small piece of code. Would appreciate help. Here is my code:

    figure
    worldmap 'botswana'
    axis off
    geoshow('landareas.shp','FaceColor',[0.5 0.7 0.5])
    geoshow('worldcities.shp','Marker','.','Color','red', 'MarkerSize', 25)
    q = circlem(24.65,25.91,500, 'facecolor', 'red')