Home My Page Projects Code Snippets Project Openings diderot
Summary Activity Tracker Tasks SCM

SCM Repository

[diderot] Diff of /branches/charisee/TODO
ViewVC logotype

Diff of /branches/charisee/TODO

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 1156, Sun May 8 21:20:52 2011 UTC revision 1301, Thu Jun 9 23:58:40 2011 UTC
# Line 1  Line 1 
1  NOTE: GLK's approximate ranking of 5 most important tagged with  NOTE: GLK's approximate ranking of 8 most important tagged with
2  [GLK:1], [GLK:2], ...  [GLK:1], [GLK:2], ...
3    
4  ========================  ========================
5  SHORT TERM ============= (*needed* for streamlines & tractography)  SHORT TERM ============= (*needed* for streamlines & tractography)
6  ========================  ========================
7    
8  [GLK:1] Add sequence types (needed for evals & evecs)  Remove CL from compiler
9    
10    [GLK:3] Add sequence types (needed for evals & evecs)
11      syntax      syntax
12          types: ty '{' INT '}'          types: ty '{' INT '}'
13          value construction: '{' e1 ',' … ',' en '}'          value construction: '{' e1 ',' … ',' en '}'
14          indexing: e '{' e '}'          indexing: e '{' e '}'
15  [GLK:1] evals & evecs for symmetric tensor[3,3] (requires sequences)  
16    [GLK:4] evals & evecs for symmetric tensor[2,2] and
17    tensor[3,3] (requires sequences)
18    
19  ability to emit/track/record variables into dynamically re-sized  ability to emit/track/record variables into dynamically re-sized
20  runtime buffer  runtime buffer
# Line 18  Line 22 
22  tensor fields: convolution on general tensor images  tensor fields: convolution on general tensor images
23    
24  ========================  ========================
25  SHORT-ISH TERM ========= (to make using Diderot less annoying/slow)  SHORT-ISH TERM ========= (to make using Diderot less annoying to
26  ========================  ========================  program in, and slow to execute)
27    
28    value-numbering optimization [DONE]
29    
30  value-numbering optimization  Allow ".ddro" file extensions in addition to ".diderot"
31    
32    Be able to output values of type tensor[2,2] and tensor[3,3];
33    (currently only scalars & vectors).  Want to add some regression tests
34    based on this and currently can't
35    
36    [GLK:1] Add a clamp function, which takes three arguments; either
37    three scalars:
38      clamp(lo, hi, x)  = max(lo, min(hi, x))
39    or three vectors of the same size:
40      clamp(lo, hi, [x,y])  = [max(lo[0], min(hi[0], x)),
41                               max(lo[1], min(hi[1], y))]
42    This would be useful in many current Diderot programs.
43    One question: clamp(x, lo, hi) is the argument order used in OpenCL
44    and other places, but clamp(lo, hi, x) is much more consistent with
45    lerp(lo, hi, x), hence GLK's preference
46    [DONE]
47    
48    [GLK:2] Proper handling of stabilize method
49    
50    allow "*" to represent "modulate": per-component multiplication of
51    vectors, and vectors only (not tensors of order 2 or higher).  Once
52    sequences are implemented this should be removed: the operation is not
53    invariant WRT basis so it is not a legit vector computation.
54    
55  proper handling of stabilize method  implicit type promotion of integers to reals where reals are
56    required (e.g. not exponentiation "^")
57    
58  [GLK:2] Save Diderot output to nrrd, instead of "mip.txt"  [GLK:5] Save Diderot output to nrrd, instead of "mip.txt"
59    For grid of strands, save to similarly-shaped array    For grid of strands, save to similarly-shaped array
60    For list of strands, save to long 1-D (or 2-D for non-scalar output) list    For list of strands, save to long 1-D (or 2-D for non-scalar output) list
61    For ragged things (like tractography output), will need to save both    For ragged things (like tractography output), will need to save both
62      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
63      to index into complete list      to index into complete list
64    
65  [GLK:3] Use of Teem's "hest" command-line parser for getting  [GLK:6] Use of Teem's "hest" command-line parser for getting
66  any input variables that are not defined in the source file  any "input" variables that are not defined in the source file.
67    
68  [GLK:4] ability to declare a field so that probe positions are  [GLK:7] ability to declare a field so that probe positions are
69  *always* "inside"; with various ways of mapping the known image values  *always* "inside"; with various ways of mapping the known image values
70  to non-existant index locations.  One possible syntax emphasizes that  to non-existant index locations.  One possible syntax emphasizes that
71  there is a index mapping function that logically precedes convolution:  there is a index mapping function that logically precedes convolution:
72    F = bspln3 ⊛ (img  clamp)    F = bspln3 ⊛ (img ◦ clamp)
73    F = bspln3 ⊛ (img ◦ repeat)    F = bspln3 ⊛ (img ◦ repeat)
74    F = bspln3 ⊛ (img ◦ mirror)    F = bspln3 ⊛ (img ◦ mirror)
75  where "◦" or "∘" is used to indicate function composition  where "◦" or "∘" is used to indicate function composition
76    
 Use ∇⊗ etc. syntax  
     syntax [DONE]  
     typechecking  
     IL and codegen  
   
 Add a clamp function, which takes three arguments; either three scalars:  
   clamp(x, minval, maxval)  = max(minval, min(maxval, x))  
 or three vectors of the same size:  
   clamp([x,y], minvec, maxvec)  = [max(minvec[0], min(maxvec[0], x)),  
                                    max(minvec[1], min(maxvec[1], y))]  
 This would be useful in many current Diderot programs.  
 One question: clamp(x, minval, maxval) is the argument order  
 used in OpenCL and other places, but clamp(minval, maxval, x)  
 would be more consistent with lerp(minout, maxout, x).  
   
77  Level of differentiability in field type should be statement about how  Level of differentiability in field type should be statement about how
78  much differentiation the program *needs*, rather than what the kernel  much differentiation the program *needs*, rather than what the kernel
79  *provides*.  The needed differentiability can be less than or equal to  *provides*.  The needed differentiability can be less than or equal to
80  the provided differentiability.  the provided differentiability.
81    
82    Use ∇⊗ etc. syntax
83        syntax [DONE]
84        typechecking
85        IL and codegen
86    
87  Add type aliases for color types  Add type aliases for color types
88      rgb = real{3}      rgb = real{3}
89      rgba = real{4}      rgba = real{4}
# Line 76  Line 96 
96    
97  "initially" supports lists  "initially" supports lists
98    
99  "initially" supports lists of positions output from  "initially" supports lists of positions output from different
100  different initalization Diderot program  initalization Diderot program (or output from the same program;
101    e.g. using output of iso2d.diderot for one isovalue to seed the input
102    to another invocation of the same program)
103    
104  Communication between strands: they have to be able to learn each  Communication between strands: they have to be able to learn each
105  other's state (at the previous iteration).  Early version of this can  other's state (at the previous iteration).  Early version of this can
# Line 94  Line 116 
116    
117  support for Python interop and GUI  support for Python interop and GUI
118    
119    Allow integer exponentiation ("^2") to apply to square matrices,
120    to represent repeated matrix multiplication
121    
122  Alow X *= Y, X /= Y, X += Y, X -= Y to mean what they do in C,  Alow X *= Y, X /= Y, X += Y, X -= Y to mean what they do in C,
123  provided that X*Y, X/Y, X+Y, X-Y are already supported.  provided that X*Y, X/Y, X+Y, X-Y are already supported.
124  Nearly every Diderot program would be simplified by this.  Nearly every Diderot program would be simplified by this.
125    [DONE]
126    
127  Put small 1-D and 2-D fields, when reconstructed specifically by tent  Put small 1-D and 2-D fields, when reconstructed specifically by tent
128  and when differentiation is not needed, into faster texture buffers.  and when differentiation is not needed, into faster texture buffers.
129  test/illust-vr.diderot is good example of program that uses multiple  test/illust-vr.diderot is good example of program that uses multiple
130  such 1-D fields basically as lookup-table-based function evaluation  such 1-D fields basically as lookup-table-based function evaluation
131    
132  expand trace in mid to low translation  expand trace in mid to low translation [DONE]
133    
134  extend norm (|exp|) to all tensor types [DONE for vectors and matrices]  extend norm (|exp|) to all tensor types [DONE for vectors and matrices]
135    
# Line 142  Line 168 
168  (but we should only duplicate over the live-range of the result of the  (but we should only duplicate over the live-range of the result of the
169  conditional.  conditional.
170    
171  [GLK:5] Want: non-trivial field expressions & functions:  [GLK:8] Want: non-trivial field expressions & functions.
172    scalar fields from scalar fields F and G:
173      field#0(2)[] X = (sin(F) + 1.0)/2;
174      field#0(2)[] X = F*G;
175    scalar field of vector field magnitude:
176    image(2)[2] Vimg = load(...);    image(2)[2] Vimg = load(...);
177    field#0(2)[] Vlen = |Vimg ⊛ bspln3|;    field#0(2)[] Vlen = |Vimg ⊛ bspln3|;
178  to get a scalar field of vector length, or  field of normalized vectors (for LIC and vector field feature extraction)
179      field#2(2)[2] F = ...
180      field#0(2)[2] V = normalize(F);
181    scalar field of gradient magnitude (for edge detection))
182    field#2(2)[] F = Fimg ⊛ bspln3;    field#2(2)[] F = Fimg ⊛ bspln3;
183    field#0(2)[] Gmag = |∇F|;    field#0(2)[] Gmag = |∇F|;
184  to get a scalar field of gradient magnitude, or  scalar field of squared gradient magnitude (simpler to differentiate):
185    field#2(2)[] F = Fimg ⊛ bspln3;    field#2(2)[] F = Fimg ⊛ bspln3;
186    field#0(2)[] Gmsq = ∇F•∇F;    field#0(2)[] Gmsq = ∇F•∇F;
187  to get a scalar field of squared gradient magnitude, which is simpler  There is value in having these, even if the differentiation of them is
188  to differentiate.  However, there is value in having these, even if  not supported (hence the indication of "field#0" for these above)
 the differentiation of them is not supported (hence the indication  
 of "field#0" for these above)  
   
 Want: ability to apply "normalize" to a field itself, e.g.  
   field#0(2)[2] V = normalize(Vimg ⊛ ctmr);  
 so that V(x) = normalize((Vimg ⊛ ctmr)(x)).  
 Having this would simplify expression of standard LIC method, and  
 would also help express other vector field expressions that arise  
 in vector field feature exraction.  
189    
190  Permit fields composition, especially for warping images by a  Introduce region types (syntax region(d), where d is the dimension of the
191  smooth field of deformation vectors  region.  One useful operator would be
192            dom : field#k(d)[s] -> region(d)
193    Then the inside test could be written as
194            pos ∈ dom(F)
195    We could further extend this approach to allow geometric definitions of
196    regions.  It might also be useful to do inside tests in world space,
197    instead of image space.
198    
199    co- vs contra- index distinction
200    
201    Permit field composition:
202    field#2(3)[3] warp = bspln3 ⊛ warpData;    field#2(3)[3] warp = bspln3 ⊛ warpData;
203    field#2(3)[] F = bspln3 ⊛ img;    field#2(3)[] F = bspln3 ⊛ img;
204    field#2(3)[] Fwarp = F ◦ warp;    field#2(3)[] Fwarp = F ◦ warp;
205  So Fwarp(x) = F(warp(X)).  Chain rule can be used for differentation  So Fwarp(x) = F(warp(X)).  Chain rule can be used for differentation.
206    This will be instrumental for expressing non-rigid registration
207    methods (but those will require co-vs-contra index distinction)
208    
209  Allow the convolution to be specified either as a single 1D kernel  Allow the convolution to be specified either as a single 1D kernel
210  (as we have it now):  (as we have it now):
211    field#2(3)[] F = bspln3 ⊛ img;    field#2(3)[] F = bspln3 ⊛ img;
212  or, as a tensor product of kernels, one for each axis, e.g.  or, as a tensor product of kernels, one for each axis, e.g.
213    field#0(3)[] F = (bspln3 ⊗ bspln3 ⊗ tent) ⊛ img;    field#0(3)[] F = (bspln3 ⊗ bspln3 ⊗ tent) ⊛ img;
214  This is especially important for things like time-varying data, or  This is especially important for things like time-varying fields
215  other multi-dimensional fields where one axis of the domain is very  and the use of scale-space in field visualization: one axis of the
216  different from the rest.  What is very unclear is how, in such cases,  must be convolved with a different kernel during probing.
217  we should notate the gradient, when we only want to differentiate with  What is very unclear is how, in such cases, we should notate the
218  respect to some of the axes.  gradient, when we only want to differentiate with respect to some
219    subset of the axes.  One ambitious idea would be:
220      field#0(3)[] Ft = (bspln3 ⊗ bspln3 ⊗ tent) ⊛ img; // 2D time-varying field
221      field#0(2)[] F = lambda([x,y], Ft([x,y,42.0]))     // restriction to time=42.0
222      vec2 grad = ∇F([x,y]);                             // 2D gradient
223    
224    Tensors of order 3 (e.g. gradients of diffusion tensor fields, or
225    hessians of vector fields) and order 4 (e.g. Hessians of diffusion
226    tensor fields).
227    
228  co- vs contra- index distinction  representation of tensor symmetry
   
 some indication of tensor symmetry  
229  (have to identify the group of index permutations that are symmetries)  (have to identify the group of index permutations that are symmetries)
230    
231  dot works on all tensors  dot works on all tensors
232    
233  outer works on all tensors  outer works on all tensors
234    
235    Help for debugging Diderot programs: need to be able to uniquely
236    identify strands, and for particular strands that are known to behave
237    badly, do something like printf or other logging of their computations
238    and updates.
239    
240    Permit writing dimensionally general code: Have some statement of the
241    dimension of the world "W" (or have it be learned from one particular
242    field of interest), and then able to write "vec" instead of
243    "vec2/vec3", and perhaps "tensor[W,W]" instead of
244    "tensor[2,2]/tensor[3,3]"
245    
246    Traits: all things things that have boilerplate code (especially
247    volume rendering) should be expressed in terms of the unique
248    computational core.  Different kinds of streamline/tractography
249    computation will be another example, as well as particle systems.
250    
251  Einstein summation notation  Einstein summation notation
252    
253  "tensor comprehension" (like list comprehension)  "tensor comprehension" (like list comprehension)
254    
255    Fields coming from different sources of data:
256    * triangular or tetrahedral meshes over 2D or 3D domains (of the
257      source produced by finite-element codes; these will come with their
258      own specialized kinds of reconstruction kernels, called "basis
259      functions" in this context)
260    * Large point clouds, with some radial basis function around each point,
261      which will be tuned by parameters of the point (at least one parameter
262      giving some notion of radius)
263    
264  ======================  ======================
265  BUGS =================  BUGS =================
266  ======================  ======================

Legend:
Removed from v.1156  
changed lines
  Added in v.1301

root@smlnj-gforge.cs.uchicago.edu
ViewVC Help
Powered by ViewVC 1.0.0