5 
SHORT TERM ============= (*needed* for streamlines & tractography) 
SHORT TERM ============= (*needed* for streamlines & tractography) 
6 
======================== 
======================== 
7 


8 
Remove CL from compiler 
[GLK:2] Add sequence types (needed for evals & evecs) 




[GLK:3] Add sequence types (needed for evals & evecs) 

9 
syntax 
syntax 
10 
types: ty '{' INT '}' 
types: ty '{' INT '}' 
11 
value construction: '{' e1 ',' … ',' en '}' 
value construction: '{' e1 ',' … ',' en '}' 
12 
indexing: e '{' e '}' 
indexing: e '{' e '}' 
13 


14 
[GLK:4] evals & evecs for symmetric tensor[2,2] and 
[GLK:3] evals & evecs for symmetric tensor[2,2] and 
15 
tensor[3,3] (requires sequences) 
tensor[3,3] (requires sequences) 
16 


17 
ability to emit/track/record variables into dynamically resized 
ability to emit/track/record variables into dynamically resized 
18 
runtime buffer 
runtime output buffer 
19 


20 
tensor fields: convolution on general tensor images 
[GLK:4] tensor fields from tensor images: Initially need at least 
21 

convolution on tensor[2,2] and tensor[3,3] (the same componentwise 
22 

convolution as for vectors). 
23 


24 
======================== 
======================== 
25 
SHORTISH TERM ========= (to make using Diderot less annoying to 
SHORTISH TERM ========= (to make using Diderot less annoying to 
26 
======================== program in, and slow to execute) 
======================== program in, and slow to execute) 
27 



valuenumbering optimization [DONE] 




28 
Allow ".ddro" file extensions in addition to ".diderot" 
Allow ".ddro" file extensions in addition to ".diderot" 
29 


30 
Be able to output values of type tensor[2,2] and tensor[3,3]; 
Be able to output values of type tensor[2,2] and tensor[3,3]; 
31 
(currently only scalars & vectors). Want to add some regression tests 
(currently only scalars & vectors). Want to add some regression tests 
32 
based on this and currently can't 
based on this and currently can't 
33 


34 
[GLK:1] Add a clamp function, which takes three arguments; either 
[GLK:1] Proper handling of stabilize method 

three scalars: 


clamp(lo, hi, x) = max(lo, min(hi, x)) 


or three vectors of the same size: 


clamp(lo, hi, [x,y]) = [max(lo[0], min(hi[0], x)), 


max(lo[1], min(hi[1], y))] 


This would be useful in many current Diderot programs. 


One question: clamp(x, lo, hi) is the argument order used in OpenCL 


and other places, but clamp(lo, hi, x) is much more consistent with 


lerp(lo, hi, x), hence GLK's preference 


[DONE] 

35 


36 
[GLK:2] Proper handling of stabilize method 
Convolution on general tensor images (order > 2) 
37 


38 
allow "*" to represent "modulate": percomponent multiplication of 
allow "*" to represent "modulate": percomponent multiplication of 
39 
vectors, and vectors only (not tensors of order 2 or higher). Once 
vectors, and vectors only (not tensors of order 2 or higher). Once 
43 
implicit type promotion of integers to reals where reals are 
implicit type promotion of integers to reals where reals are 
44 
required (e.g. not exponentiation "^") 
required (e.g. not exponentiation "^") 
45 


46 
[GLK:5] Save Diderot output to nrrd, instead of "mip.txt" 
[Nick working on this] Save Diderot output to nrrd, instead of "mip.txt" 
47 
For grid of strands, save to similarlyshaped array 
For grid of strands, save to similarlyshaped array 
48 
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 
49 
For ragged things (like tractography output), will need to save both 
For ragged things (like tractography output), will need to save both 
50 
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 
51 
to index into complete list 
to index into complete list 
52 


53 
[GLK:6] Use of Teem's "hest" commandline parser for getting 
[GLK:6] ability to declare a field so that probe positions are 

any "input" variables that are not defined in the source file. 





[GLK:7] ability to declare a field so that probe positions are 

54 
*always* "inside"; with various ways of mapping the known image values 
*always* "inside"; with various ways of mapping the known image values 
55 
to nonexistant index locations. One possible syntax emphasizes that 
to nonexistant index locations. One possible syntax emphasizes that 
56 
there is a index mapping function that logically precedes convolution: 
there is a index mapping function that logically precedes convolution: 
73 
rgb = real{3} 
rgb = real{3} 
74 
rgba = real{4} 
rgba = real{4} 
75 


76 

Revisit how images are created within the language. 
77 

The "load" operator should probably go away, and its strangs 
78 

that strings are there only as a way to refer to nrrd filenames 
79 


80 
============================== 
============================== 
81 
MEDIUM TERM ================== (*needed* for particles) 
MEDIUM TERM ================== (*needed* for particles) 
82 
============================== 
============================== 
83 


84 
runtime birth of strands 
[Lamont working on this] runtime birth of strands 
85 


86 
"initially" supports lists 
"initially" supports lists 
87 


90 
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 
91 
to another invocation of the same program) 
to another invocation of the same program) 
92 


93 
Communication between strands: they have to be able to learn each 
[Lamont working on this] Communication between strands: they have to 
94 
other's state (at the previous iteration). Early version of this can 
be able to learn each other's state (at the previous iteration). 
95 
have the network of neighbors be completely static (for running one 
Early version of this can have the network of neighbors be completely 
96 
strand/pixel image computations). Later version with strands moving 
static (for running one strand/pixel image computations). Later 
97 
through the domain will require some spatial data structure to 
version with strands moving through the domain will require some 
98 
optimize discovery of neighbors. 
spatial data structure to optimize discovery of neighbors. 
99 


100 
============================ 
============================ 
101 
MEDIUMISH TERM ============ (to make Diderot more useful/effective) 
MEDIUMISH TERM ============ (to make Diderot more useful/effective) 
102 
============================ 
============================ 
103 


104 

[GLK:5] Want codegeneration working for tensors of order three. 
105 

Order three matters for edge detection in scalar fields (to get 
106 

second derivatives of gradient magnitude), second derivatives 
107 

of vector fields (for some feature extraction), and first 
108 

derivatives of diffusion tensor fields. 
109 


110 
Python/ctypes interface to runtime 
Python/ctypes interface to runtime 
111 


112 
support for Python interop and GUI 
support for Python interop and GUI 
114 
Allow integer exponentiation ("^2") to apply to square matrices, 
Allow integer exponentiation ("^2") to apply to square matrices, 
115 
to represent repeated matrix multiplication 
to represent repeated matrix multiplication 
116 



Alow X *= Y, X /= Y, X += Y, X = Y to mean what they do in C, 


provided that X*Y, X/Y, X+Y, XY are already supported. 


Nearly every Diderot program would be simplified by this. 


[DONE] 




117 
Put small 1D and 2D fields, when reconstructed specifically by tent 
Put small 1D and 2D fields, when reconstructed specifically by tent 
118 
and when differentiation is not needed, into faster texture buffers. 
and when differentiation is not needed, into faster texture buffers. 
119 
test/illustvr.diderot is good example of program that uses multiple 
test/illustvr.diderot is good example of program that uses multiple 
120 
such 1D fields basically as lookuptablebased function evaluation 
such 1D fields basically as lookuptablebased function evaluation 
121 



expand trace in mid to low translation 




122 
extend norm (exp) to all tensor types [DONE for vectors and matrices] 
extend norm (exp) to all tensor types [DONE for vectors and matrices] 
123 


124 
determinant ("det") for tensor[3,3] 
determinant ("det") for tensor[3,3] 
142 
tensor construction [DONE] 
tensor construction [DONE] 
143 
tensor indexing [DONE] 
tensor indexing [DONE] 
144 
tensor slicing 
tensor slicing 

verify that hessians work correctly [DONE] 

145 


146 
Better handling of variables that determines the scope of a variable 
Better handling of variables that determines the scope of a variable 
147 
based on its actual use, instead of where the user defined it. So, 
based on its actual use, instead of where the user defined it. So, 
155 
(but we should only duplicate over the liverange of the result of the 
(but we should only duplicate over the liverange of the result of the 
156 
conditional. 
conditional. 
157 


158 
[GLK:8] Want: nontrivial field expressions & functions. 
[GLK:7] Want: nontrivial field expressions & functions. 
159 
scalar fields from scalar fields F and G: 
scalar fields from scalar fields F and G: 
160 
field#0(2)[] X = (sin(F) + 1.0)/2; 
field#0(2)[] X = (sin(F) + 1.0)/2; 
161 
field#0(2)[] X = F*G; 
field#0(2)[] X = F*G; 
208 
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 
209 
vec2 grad = ∇F([x,y]); // 2D gradient 
vec2 grad = ∇F([x,y]); // 2D gradient 
210 



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). 




211 
representation of tensor symmetry 
representation of tensor symmetry 
212 
(have to identify the group of index permutations that are symmetries) 
(have to identify the group of index permutations that are symmetries) 
213 


253 
// uncaught exception Size [size] 
// uncaught exception Size [size] 
254 
// raised at ctarget/ctarget.sml:47.1547.19 
// raised at ctarget/ctarget.sml:47.1547.19 
255 
//field#4(3)[] F = img ⊛ bspln5; 
//field#4(3)[] F = img ⊛ bspln5; 
256 

