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THIS TODO HAS BEEN MOVED TO THE DIDEROT WIKI: 
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http://diderotwiki.cs.uchicago.edu/index.php/Todo 
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PLEASE USE THAT PAGE TO UPDATE PROBLEMS AND PROGRESS 
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NOTE: GLK's approximate ranking of 8 most important tagged with 
NOTE: GLK's approximate ranking of 8 most important tagged with 
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[GLK:1], [GLK:2], ... 
[GLK:1], [GLK:2], ... 
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ability to emit/track/record variables into dynamically resized 
ability to emit/track/record variables into dynamically resized 
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runtime output buffer 
runtime output buffer 
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tensor fields: convolution on general tensor images (order > 1) 
[GLK:4] tensor fields from tensor images: Initially need at least 
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convolution on tensor[2,2] and tensor[3,3] (the same componentwise 
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convolution as for vectors). 
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======================== 
======================== 
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SHORTISH TERM ========= (to make using Diderot less annoying to 
SHORTISH TERM ========= (to make using Diderot less annoying to 
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[GLK:1] Proper handling of stabilize method 
[GLK:1] Proper handling of stabilize method 
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Convolution on general tensor images (order > 2) 
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allow "*" to represent "modulate": percomponent multiplication of 
allow "*" to represent "modulate": percomponent multiplication of 
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vectors, and vectors only (not tensors of order 2 or higher). Once 
vectors, and vectors only (not tensors of order 2 or higher). Once 
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sequences are implemented this should be removed: the operation is not 
sequences are implemented this should be removed: the operation is not 
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implicit type promotion of integers to reals where reals are 
implicit type promotion of integers to reals where reals are 
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required (e.g. not exponentiation "^") 
required (e.g. not exponentiation "^") 
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[GLK:4] Save Diderot output to nrrd, instead of "mip.txt" 
[Nick working on this] Save Diderot output to nrrd, instead of "mip.txt" 
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For grid of strands, save to similarlyshaped array 
For grid of strands, save to similarlyshaped array 
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For list of strands, save to long 1D (or 2D for nonscalar output) list 
For list of strands, save to long 1D (or 2D for nonscalar output) list 
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For ragged things (like tractography output), will need to save both 
For ragged things (like tractography output), will need to save both 
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complete list of values, as well as list of start indices and lengths 
complete list of values, as well as list of start indices and lengths 
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to index into complete list 
to index into complete list 
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[GLK:5] ability to declare a field so that probe positions are 
[GLK:6] ability to declare a field so that probe positions are 
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*always* "inside"; with various ways of mapping the known image values 
*always* "inside"; with various ways of mapping the known image values 
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to nonexistant index locations. One possible syntax emphasizes that 
to nonexistant index locations. One possible syntax emphasizes that 
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there is a index mapping function that logically precedes convolution: 
there is a index mapping function that logically precedes convolution: 
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rgba = real{4} 
rgba = real{4} 
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Revisit how images are created within the language. 
Revisit how images are created within the language. 
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The "load" operator should probably go away, and its strangs 
The "load" operator should probably go away, and its strange 
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that strings are there only as a way to refer to nrrd filenames 
that strings are there only as a way to refer to nrrd filenames 
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============================== 
============================== 
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MEDIUM TERM ================== (*needed* for particles) 
MEDIUM TERM ================== (*needed* for particles) 
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============================== 
============================== 
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runtime birth of strands 
[Lamont working on this] runtime birth of strands 
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"initially" supports lists 
"initially" supports lists 
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e.g. using output of iso2d.diderot for one isovalue to seed the input 
e.g. using output of iso2d.diderot for one isovalue to seed the input 
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to another invocation of the same program) 
to another invocation of the same program) 
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Communication between strands: they have to be able to learn each 
[Lamont working on this] Communication between strands: they have to 
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other's state (at the previous iteration). Early version of this can 
be able to learn each other's state (at the previous iteration). 
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have the network of neighbors be completely static (for running one 
Early version of this can have the network of neighbors be completely 
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strand/pixel image computations). Later version with strands moving 
static (for running one strand/pixel image computations). Later 
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through the domain will require some spatial data structure to 
version with strands moving through the domain will require some 
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optimize discovery of neighbors. 
spatial data structure to optimize discovery of neighbors. 
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============================ 
============================ 
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MEDIUMISH TERM ============ (to make Diderot more useful/effective) 
MEDIUMISH TERM ============ (to make Diderot more useful/effective) 
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============================ 
============================ 
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[GLK:5] Want codegeneration working for tensors of order three. 
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Order three matters for edge detection in scalar fields (to get 
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second derivatives of gradient magnitude), second derivatives 
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of vector fields (for some feature extraction), and first 
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derivatives of diffusion tensor fields. 
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Python/ctypes interface to runtime 
Python/ctypes interface to runtime 
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support for Python interop and GUI 
support for Python interop and GUI 
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LONG TERM ==================== (make Diderot more interesting/attractive from 
LONG TERM ==================== (make Diderot more interesting/attractive from 
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============================== a research standpoint) 
============================== a research standpoint) 
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[GLK:6] Want codegeneration working for tensors of order three. 


Order three matters for edge detection in scalar fields (to get 


second derivatives of gradient magnitude), second derivatives 


of vector fields (for some feature extraction), and first 


derivatives of diffusion tensor fields. 




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IL support for higherorder tensor values (matrices, etc). 
IL support for higherorder tensor values (matrices, etc). 
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tensor construction [DONE] 
tensor construction [DONE] 
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tensor indexing [DONE] 
tensor indexing [DONE] 
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field#0(2)[] F = lambda([x,y], Ft([x,y,42.0])) // restriction to time=42.0 
field#0(2)[] F = lambda([x,y], Ft([x,y,42.0])) // restriction to time=42.0 
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vec2 grad = ∇F([x,y]); // 2D gradient 
vec2 grad = ∇F([x,y]); // 2D gradient 
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Tensors of order 3 (e.g. gradients of diffusion tensor fields, or 


hessians of vector fields) and order 4 (e.g. Hessians of diffusion 


tensor fields). 




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representation of tensor symmetry 
representation of tensor symmetry 
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(have to identify the group of index permutations that are symmetries) 
(have to identify the group of index permutations that are symmetries) 
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