title: missing required architecture x86_64 in file libCorePlot-CocoaTouch.a
body: <p><strong>According to the <a href="http://www.raywenderlich.com/13269/how-to-draw-graphs-with-core-plot-part-1">Ray Wenderlich tutorial</a>, I done the following :</strong></p>
  
  <p><em><strong>Step 1 -</em></strong> I downloaded <strong><a href="http://code.google.com/p/core-plot/downloads/detail?name=CorePlot_1.4.zip&amp;can=2&amp;q=">CorePlot_1.4.zip</a></strong> on the official website</p>
  
  <p><em><strong>Step 2 -</em></strong> I added to my project the <strong>CorePlotHeaders folder</strong> and the <strong>static library named libCorePlot-CocoaTouch.a</strong> (checking <em>“Copy items into destination group’s folder (if needed)”</em>)</p>
  
  <p><em><strong>Step 3 -</em></strong> I added into <strong>Other Linker Flags field</strong> the following : <strong>-ObjC</strong></p>
  
  <p><em><strong>Step 4</em></strong> - I checked into <strong>Link Binary with Libraries</strong> if <strong>libCorePlot-CocoaTouch.a</strong> and <strong>QuartzCore</strong> frameworks were here</p>
  
  <p><em><strong>Result :</em></strong> When I compile my project, it works fine when I'm using <strong>Iphone Retina (4-Inch)</strong>. But when I'm using <strong>Iphone Retina (4-Inch 64-bit)</strong>
  I got the following message when I try to build and run :</p>
  
  <p><code>ld: warning: ignoring file /blah/blah/libCorePlot-CocoaTouch.a, missing required architecture x86_64 in file /blah/blah/libCorePlot-CocoaTouch.a (3 slices)</code></p>
  
  <p><em><strong>Here the complete message :</em></strong></p>
  
  <pre><code>ld: warning: ignoring file /Users/me/Desktop/project/libCorePlot-CocoaTouch.a, missing required architecture x86_64 in file /Users/me/Desktop/project/libCorePlot-CocoaTouch.a (3 slices)
  Undefined symbols for architecture x86_64:
  "_CPTDecimalFromCGFloat", referenced from:
    -[PatientConstanteVisualiser configurePlots] in PatientConstanteVisualiser.o
    -[PatientConstanteVisualiser configureAxes] in PatientConstanteVisualiser.o
  "_CPTDecimalFromInteger", referenced from:
    -[PatientConstanteVisualiser configureAxes] in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTAxisLabel", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTColor", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTFill", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTMutableLineStyle", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTMutableTextStyle", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTPlotSymbol", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTScatterPlot", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTTheme", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_OBJC_CLASS_$_CPTXYGraph", referenced from:
    objc-class-ref in PatientConstanteVisualiser.o
  "_kCPTStocksTheme", referenced from:
    -[PatientConstanteVisualiser configureGraph] in PatientConstanteVisualiser.o
  ld: symbol(s) not found for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>I spent several hours on this issue... Please help...</p>