The documentation for the AnalyserNode doesn't specify what reference suffix is used for analyser.maxDecibels or analyser.minDecibels Does anyone happen to know what that suffix is?
The FFT Windowing section (See Conversion to dB) tells how the AnalyserNode computes the dB values.
Not really sure what you mean by "reference suffix".
Related
I am reading covariance data from flat files. For that reason, not being able to fully read the floating number results in covarince not satisfying positive semi definite requirements.
For instance, this is one of the input from raw text:
“-0.581050672”— no, actually raw text is this: -5.801050672E-01
When I read this into kdb and cast with F, it results in -0.50810507. When I do this for all and check the covariance, unfortunately it does not satisfy PSD constraints. Other hack I have been doing is to add small noise in Identity matrix…
Apart from this hack, is there way to read above data into proper floating number up to 9th digit? I tried \P and .Q.f but these only seem to work in Display.
Thank you
Sorry, does not seem like a kdb issue. Was exporting these data into different software and floating points were lost during this process. Thanks for pointer.
I met an error during initialization when using ThermoSysPro library.
It seems like the Turbine5.Pe is larger than Turbine2.Pe, so the result is negative. but I checked my parameters, there shouldn't be such a problem.
Is this because the nonlinear solver couldn't solve the equation in the following picture?
There is not enough information and I would recommend to set Details and/or Nonlinear iterations in Simulation setup>Debug>Nonlinear solver diagnostics to get more information.
The full expression causing the problem is sqrt((Turbine2.Pe^2-Turbine5.Pe^2)/(Turbine2.Cst*Turbine2.proe.T))
Since the two Pe-values have fixed=true it seems unlikely that they are wrong, but it is impossible to see without the complete model.
However, it is also possible that either Cst or proe.T is negative, or computed to a negative value based on other values.
Without a complete model that is impossible to tell.
According to the comparison between ThermoSysPro(Open source library from EDF https://github.com/alex19941215/ThermoSysPro ) and ThermalPower(Commercial library from Modelon https://www.modelon.com/library/thermal-power-library ), there should be some inspiration for people faced with the same situation.
Here is the code form ThermoSysPro library:
Connectors.FluidInlet Ce
Connectors.FluidOutlet Cs
Here is a type code from Thermal Power library:
Interfaces.FlowPort feed(
h_outflow(start=hstartin))
Interfaces.FlowPort drain(
p(start=pstart),
h_outflow(start=hstartout))
From the code, we can see that in the Thermal Power library each connector's attribute is assigned values according to the parameters, but in the ThermoSysPro library, the connector is using default values, probably zero. So that's why the Thermal Power library has better performance in the term of initialization convergence
The Matlab documentation seems unclear about how to ignore missing data when using kruskalwallis, the Kruskal-Wallis (or any other related) test. The same goes for unequal group size.
Very late answer, but I ran into the same problem myself today, might as well help some future searcher.
The solution is pretty straightforward. kruskalwallis is primarily used on matrices and by default compares equal-sized columns, but it does allow you to instead assign groups manually, with the optional variable "group". I was attempting to check whether a single value was unlikely to belong to a distribution from a different set, so this was straightforward. I just added the value I wanted to test on to the end of the set I was testing against, then made "group" a vector of ones the same size as the set, with a "2" added to the end for the new value. Looks like it worked quite nicely.
For numeric data, the the standard missing data value in Matlab is NaN. See ismissing. See also this article from The MathWorks. For tables, you might find standardizeMissing helpful as well as replaceWithMissing for dataset objects. I can't say anything about group size.
I guess this is something from new version of Matlab. But I can't figure out what does ~ represent.
SomeFundtion(hObject,~)
%function content here
Any clue would be appreciated.
In addition, maybe it's me but I can't always find a good resource to find this kind of special operator in matlab. Any recommendation of good resource for matlab?
It is used to ignore function inputs. Related MATLAB reference page tells:
Use this operator when your function must accept a predefined set of
inputs, but your function does not use all of the inputs. Common
applications include defining callback functions, as shown here, or
deriving a class from a superclass.
You may refer to the reference for example code.
Tilde is also used for ignoring some outputs. You may refer to the answers here for that kind of usage.
I have written matlab codes for two different block matching algorithms, extensive search and three step search, but i am not sure how i can check whether i am getting the correct results. Is there any standard way to check these or any standard code which i can run and compare my result with.I read somewhere that JM software can be used but i didnt find any way to use it.
You can always use the results produced by your algorithms to create the next frame of video and then analyze its quality by either visually inspecting it (which is rather subjective, and we like to deal in numbers) or calculating the mean square error between the produced image and the one you're trying to estimate. Mean square error of the exhaustive (extensive) search should be lower than the one three-step gives you.
Well, did you try to plot it? I mean,after the block-matching you have a new image, right?.
A way to know if you result if true or not is to check the sum of the difference of 2 frames.
A - pre_frame
B - post_frame
C - Compensated frame
If abs(abs(A-B)) is lower than abs(abs(A-C))) that mean it could be true.
Next time, try to specify your algoritm. Also, put your code here to help you more.