IDL 8.0 & Update on IDL Development for HDF Beau Legeer – Director Product Management (ITT-VIS)

1. IDL 8.0 & Update on IDL Development for HDFBeau Legeer – Director Product Management (ITT-VIS) September 30, 2010 HDF & HDF-EOS Workshop XIV The information contained in this document pertains to software products and services that are subject to the controls of the Export Administration Regulations (EAR). The recipient is responsible for ensuring compliance to all applicable U.S. Export Control laws and regulations.

2. IDL 8.0 Goals • Fine tuned the IDL application so it is “simple-to-drive” • With emphasis on the ad-hoc scientist user • Major IDL language enhancements that are intuitive • New control features, core data types and modern scripting syntax • Powerful graphics that are modern and easy-to-use • The best of direct graphics, object graphics and iTools • Redesigned the Help to make it easier to learn IDL • Focus on tasks and “how to” • Backward compatibility for existing code Visual Information Solutions

3. Simple UI Visual Information Solutions

4. Powerful Graphics Visual Information Solutions

5. Redesigned Help Visual Information Solutions

6. Major Language Enhancements Visual Information Solutions

7. Graphics Functions & Dot Syntax Creation – Uses a functional interface myPlot = PLOT(myData) Property Access – Uses a structure notation myPlot.color = “yellow” background = myPlot.background_color Access Elements via Strings axis = myPlot.xaxis axis.title = “Number of Farms” allAxes = myPlot[“* axis”] ; return all axes - wild card searches Visual Information Solutions

8. New Graphics Functions • Surface • Map • Mapgrid • Mapcontinents • Legend • Colorbar • Widget_Window • Vector • Streamline • Text • Polygon • Polyline • Axis • Ellipse • Plot • Barplot • Errorplot • Polarplot • Plot3D • Image • Contour Visual Information Solutions

9. New Graphics A Clean UI With Powerful Graphics • Native look & feel to the graphics window • Intuitive toolbar with interactive controls for the graphics • Programmatic control that is easy to understand for the direct graphics user • Cylindrical Equal Area map projection& other map improvements • New symbols for object graphics • PDF output from new graphics & object graphics Visual Information Solutions

10. Language Features Features of Modern Languages !NULL • Simplifies a complex, confusing operation. Other uses: • Comparison with undefined variables or null objects/pointers • Structure concatenation • Assign to variables or function results to free memory A = [ ] ; or !NULL or { } For i=0, 100 do begin A = [A, getData()] Endfor Garbage Collection • Automatic object/pointer deletion means user no longer needs to keep track of objects/pointers Visual Information Solutions

11. Language – List & Hash Methods to manage IDL variables of different types together • Arrays demand same types for each element List • Combine any IDL type together in a single data type L1 = LIST(‘spectrum', 5, 2, [1,2,3], LIST(1,2)) L1[0] = ‘Hello’ myVar = L1[0] Hash (Dictionary) • Combine any IDL type together. Elements referenced via a key H1 = HASH(‘dog', 100, ‘pig’, 200, ‘data’, findgen(100)) myVar = H1[“dog”] H1[“mykey”] = ‘Hello’ Visual Information Solutions

12. Other Language Features Control Statement • Addition of a “For Each” operator FOREACH element, variable do begin print, element ENDFOREACH New Behavior • Negative Array Indices – “Wrap-around” the end of an array A[ 0 : -1 ]  ; goes from the first element (0) to the last element (N-1) A[ -3 : 0 : -1 ]  ; goes from element N-3 down to element 0 Visual Information Solutions

13. Language – Operator Overloading Advanced Feature Perform a specific object method when an operator is performed on that object Example: Combining the values of two “length objects” to return a new value Current Syntax: With Operator Overloading: Operator overloading allows you to hide this operation. Resulting in a normal statement: The operation is placed in a method that is called when the “+” operator is used on the object: FUNCTION idl_length::_overloadPlus, lenA, lenB END length = a->GetLength() + b->GetLength() c = obj_new(‘idl_length’, length) ;; make new object c = a + b length = a->GetLength() + b->GetLength() return, obj_new(‘idl_length’, length) ; make new object Visual Information Solutions

14. What’s Overloadable # ## && || Help, Print SIZE, N_ELEMENTS FOREACH “.” is Get/SetProperty Just inherit from IDL_Object EQ NE GE GT LE LT + – * / [ ] left [ ] right NOT AND OR XOR ~ ^ mod < > Visual Information Solutions

15. Create • myObject = MyClass( ) • myObject.Cleanup • Properties: • myObject.color = ‘red’ • myColor = myObject.color • Calling Methods: • myObject.MyMethod, a, b, c • Key Points • Standard, intuitive syntax IDL 7.0 IDL 8.0 Language – Objects Before & After 8.0 A Simple Object Interaction Layer Create & Destroy myObject = OBJ_NEW(‘MyClass’) OBJ_DESTROY, myObject Properties: myObject->SetProperty,color=[255,0,0] myObject->GetProperty, color=myColor Calling Methods: myObject->MyMethod, a, b, c Key Points • Strange syntax, difficult to learn Visual Information Solutions

16. IDL 8.0 Summary • Fine tuned the IDL application so it is “simple-to-drive” • Major IDL language enhancements that are intuitive • Powerful graphics that are modern and easy-to-use • Redesigned the Help to make it easier to learn IDL • Backward compatibility for existing code Visual Information Solutions

17. IDL 8 w/HDF5 demo

18. HDF, netCDF & CDF Support in IDL 8.0 • HDF5 1.8.4 • netCDF 4.1 • CDF 3.3 • HDF-EOS 2.8 • Is the market for HDF-EOS5 growing? • HDF 4.2r3 Are there more recent significant fixes? Visual Information Solutions

19. HDF, HDF5, HDF-EOS future in IDL • Continue to update library versions • Incorporation of HDF-EOS5 based on demand • Visual data browsing for all IDL Scientific Data Formats • Implement a Common Data Model • Integration directly with IDL Workbench and Language • Incorporation of IDL 8.0 language enhancements to Scientific Data Formats • Easy to use object syntax for simple programmatic access • Reduce level of procedural calls • “Drill into” HDF objects programmatically

20. Thank You! Beau Legeer – Director of Product Management ITT-VIS blegeer@ittvis.com