Matlab openfig on headless display

Question

I'm running matlab on my local machine and I'm calling the following function from Java (running in a tomcat web server):

function df = getFig(file)
    f = openfig(file,'reuse','invisible');
    set(f, 'Color', [1,1,1]);
    df = webfigure(f);
    close(f);
end

This works fine locally but when running on our headless unix webserver we get this error:

{Error using set
Width and height must be > 0

Error in
renderwebfigure>@(childHnd,childPos)set(childHnd,'Position',[childPos(1)*parameters.width-clipRect(1)+extraRenderSpace,childPos(2)*parameters.height-clipRect(2)+extraRenderSpace,childPos(3)*parameters.width,childPos(4)*parameters.height])
(line 70)



Error in renderwebfigure>cropFigureAndReturnCData (line 70)



Error in renderwebfigure (line 31)


} 
Mar 30, 2012 4:08:17 PM org.apache.catalina.core.ApplicationContext log
INFO: WebFigures: com.mathworks.toolbox.javabuilder.services.ServiceException: com.mathworks.toolbox.javabuilder.services.ServiceException: com.mathworks.toolbox.javabuilder.services.ServiceDispatchTargetException: com.mathworks.toolbox.javabuilder.services.ServiceException: java.lang.reflect.InvocationTargetException
                at com.mathworks.toolbox.javabuilder.webfigures.WebFiguresServlet.doGet(WebFiguresServlet.java:161)
                at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
                at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
                at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
                at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
                at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
                at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
                at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
                at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
                at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
                at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
                at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
                at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964)
                at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515)
                at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:304)
                at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
                at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
                at java.lang.Thread.run(Unknown Source)
Caused by: com.mathworks.toolbox.javabuilder.services.ServiceException: com.mathworks.toolbox.javabuilder.services.ServiceDispatchTargetException: com.mathworks.toolbox.javabuilder.services.ServiceException: java.lang.reflect.InvocationTargetException
                at com.mathworks.toolbox.javabuilder.webfigures.service.request.WebFigureRenderRequest.process(WebFigureRenderRequest.java:230)
                at com.mathworks.toolbox.javabuilder.webfigures.service.request.WebFigureRenderRequest.process(WebFigureRenderRequest.java:38)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureServiceFactory$WebFigureServiceImpl.processRequest(WebFigureServiceFactory.java:61)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureServiceFactory$WebFigureServiceImpl.processRequest(WebFigureServiceFactory.java:42)
                at com.mathworks.toolbox.javabuilder.webfigures.WebFiguresServlet$1.call(WebFiguresServlet.java:147)
                at com.mathworks.toolbox.javabuilder.webfigures.WebFiguresServlet$1.call(WebFiguresServlet.java:145)
                at com.mathworks.toolbox.javabuilder.webfigures.WebFiguresServlet.doGet(WebFiguresServlet.java:158)
                ... 17 more
Caused by: com.mathworks.toolbox.javabuilder.services.ServiceDispatchTargetException: com.mathworks.toolbox.javabuilder.services.ServiceException: java.lang.reflect.InvocationTargetException
                at com.mathworks.toolbox.javabuilder.services.StatefulServicePeerCache.dispatch(StatefulServicePeerCache.java:174)
                at com.mathworks.toolbox.javabuilder.webfigures.service.request.WebFigureRenderRequest.process(WebFigureRenderRequest.java:221)
                ... 23 more
Caused by: com.mathworks.toolbox.javabuilder.services.ServiceException: java.lang.reflect.InvocationTargetException
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureBinder$WebFigurePeerImpl.renderImage(WebFigureBinder.java:260)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureBinder$WebFigurePeerImpl.renderEncoded(WebFigureBinder.java:329)
                at com.mathworks.toolbox.javabuilder.webfigures.service.request.WebFigureRenderRequest$1.execute(WebFigureRenderRequest.java:223)
                at com.mathworks.toolbox.javabuilder.webfigures.service.request.WebFigureRenderRequest$1.execute(WebFigureRenderRequest.java:221)
                at com.mathworks.toolbox.javabuilder.services.StatefulServicePeerCache.dispatch(StatefulServicePeerCache.java:171)
                ... 24 more
Caused by: java.lang.reflect.InvocationTargetException
                at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
                at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
                at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
                at java.lang.reflect.Method.invoke(Unknown Source)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureBinder$WebFigurePeerImpl$1.call(WebFigureBinder.java:254)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureBinder$WebFigurePeerImpl$1.call(WebFigureBinder.java:252)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureBinder$WebFigurePeerImpl.whileLocked(WebFigureBinder.java:191)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureBinder$WebFigurePeerImpl.renderImage(WebFigureBinder.java:252)
                ... 28 more
Caused by: com.mathworks.toolbox.javabuilder.MWException: Error using set
Width and height must be > 0
                at com.mathworks.toolbox.javabuilder.internal.MWMCR.mclFeval(Native Method)
                at com.mathworks.toolbox.javabuilder.internal.MWMCR.access$600(MWMCR.java:23)
                at com.mathworks.toolbox.javabuilder.internal.MWMCR$6.mclFeval(MWMCR.java:833)
                at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
                at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
                at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
                at java.lang.reflect.Method.invoke(Unknown Source)
                at com.mathworks.toolbox.javabuilder.internal.MWMCR$5.invoke(MWMCR.java:731)
                at $Proxy4.mclFeval(Unknown Source)
                at com.mathworks.toolbox.javabuilder.internal.MWMCR.invoke(MWMCR.java:406)
                at com.mathworks.toolbox.javabuilder.webfigures.service.WebFigureServiceMCR.renderwebfigure(WebFigureServiceMCR.java:211)
                ... 36 more

Other figures that I generate either my using plot(1:10); work fine on both platforms. So it seems the problem is with the openfig function. Also, if I path in a path to a file that doesn't exist I get a file not found error rather than the width and height must be > 0 error

Calling this however works:

function w = getplot
    f = figure('visible', 'off');
    plot(1:10);
    w = webfigure(f);
    close(f);
end

Answer 1

So it turned out for some reason the default size for these on a headless display (at least on our linux distro) is 0. This causes an error before the webfigure can be manually resized. So ultimately the fix was:

set(f, 'pos', [0 0 100 100]);