1,243 reputation
414
bio website
location Sydney, Australia
age 48
visits member for 2 years, 3 months
seen 22 hours ago

Aug
20
comment Wavelet expansion of given function (as opposed to DWT of given data)
Sorry @m_goldberg, what I meant is that that 1/31 does not appear in the Parseval's identity I mentioned, but I had to put it to make the identity work. And unfortunately it is not as simple as the iteration step, as I used wavelets with bigger support and I was not able to find such correction factor.
Aug
5
comment Find where an error occurred in a bunch of command line scripts
@Silvia, thanks. I found the issue with few Print statements here and there as you suggested. But I add that this suggestion seems even better and I will give it a go.
Aug
4
comment Find where an error occurred in a bunch of command line scripts
I've seen that @Mr.Wizard, so the parser keeps line numbers. However, once running, they are not available. I see that this could help if one runs Trace on top and use the above, but that is beyond my skills/time at the moment :)
Aug
4
comment Find where an error occurred in a bunch of command line scripts
That's what I've been doing. But when you start having more participating scripts and/or logic gets more elaborated, it becomes harder... Sad that Mathematica does not have "exceptions" but the messaging approach.
Jul
29
comment Why is either Listable or HoldFirst not working?
@Mr.Wizard, I see!
Jul
29
comment Why is either Listable or HoldFirst not working?
As suggested by @Mr.Wizard, removing HoldFirst and then just using Column[DynamicInputField[Questions[[1, 3]], ContentType -> String], BaselinePosition -> Top] works for me.
Jun
22
comment LiftingWaveletTransform with irregular grids
Thanks @eldo, but b is just a {8,8} array and, therefore, representing a signal/function in a regular grid of $(i/8,j/8)$ points, that is not irregular.
Jun
10
comment Calculate support of given wavelet
Thanks a lot @Sektor. Your comment about the "impulse response" got me thinking and I was able to arrive to something similar to yours using the "PrimalHighpass" coefficients (it is most likely the same, but I will double check with yours; fantastic.)
Jun
10
comment Calculate support of given wavelet
Thanks a lot @Sektor, but the support of second graph (wavelet) seems to be around [-6,4], isn't it? This is what confuses me, because the values for $x$ where $\psi _{j,k}(x)$ is guaranteed to be zero don't seem be just outside of [0,$2^{-j}$].
Jun
10
comment Calculate support of given wavelet
I want to use DaubechiesWavelet.
Mar
20
comment How to keep labels inside the box in BarChart3D
It does! @Kuba, you should post it as answer; happy to accept it. PlotRangePadding -> .35 is just perfect :)
Mar
20
comment How to keep labels inside the box in BarChart3D
@Kuba, thanks for asking. BarChart3D rotate the labels as you change the point of view. The 3D position and overall size seem ok for very short labels as shown in first picture, but for longer labels it seems there is not enough room to display and they overflow the bottom plane. It is a little bit pedantic on my side, I am afraid, but if there is an option to change some position or size I am willing to spend some time perfecting the drawing ;-)
Feb
16
comment Why does Mathematica evaluate Sin[2.0] but not Sin[2]?
Funnily enough, @DonComo, this N[Sin[2], 2]^2 + N[Cos[2], 2]^2 == 1 is True, although you may get a very different result in traditional programming languages. Here is what you get in Ruby (irb): ` Math.sin(2).round(2)**2 + Math.cos(2).round(2)**2 == 1` => false. The reason is that Mathematica keeps track of precision and, at the level of precision requested, the two expressions are the same :)
Feb
16
comment Measuring fractal dimension of natural objects from digital images
@VitaliyKaurov, glad you liked it. Note that Viola & Jones rightly pointed out a link between integral image and Haar wavelet basis in their paper; although this wasn't explored further. It is unclear to me the link between the paper you mentioned and fractal dimension, but certainly worth reading as I am interested in these kind of problems. Cheers.
Feb
1
comment Better way to get Fisher Exact?
Unexpected but interesting answer. Acknowledged as promised!
Jan
31
comment Better way to get Fisher Exact?
Thanks a lot @romke-bontekoe. This is for someone who expects/needs p-values as practiced usually in medicine research, i.e. from a frequentist point of view. Do you know any support of this Bayesian view in medicine/genetics? Interestingly enough, your examples are suitable for Pearson's $\chi^2$, although the test in this context is whether one has an expected matrix having the same row and column sums as the data or not. In a Bayesian view, prior knowledge of both, row and column sums, right? Again, thanks, very interesting!
Jan
30
comment BarChart3D does not print zeros and odd tick positions
@Murta, I haven't received an email to upgrade, I have 9.0.0.0 on Mac. Maybe I should contact Wolfram.
Jan
30
comment BarChart3D does not print zeros and odd tick positions
Thanks @Mr.Wizard, I have version 9.0.0.0 and it seems behaviour changed. I am happy with my workaround tough. If you can shed light on how to place the labels I will give you the answer; my current manual placing is not portable to other NxM matrices, which is bad. Cheers!
Jan
25
comment Is it possible to embed a cdf file into a GitHub Page
In addition to the embedding code, one usually needs to ensure the webserver sends the right MIME type. And afaik, github does not allow this, see
Jan
19
comment Data acquisition from a Measurement Computing USB device
Have you seen the device interface? And this guide?