In signal processing windowing allows to work on overlapping segments of the signal.
Questions tagged [windowing]
224 questions
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Programming a WPF app with MS Word-like windowing
I was wondering if this is possible? It seems like a WPF application must have one and only one MainWindow, which is the window for the application. If I create other windows and show them, will they show up as separate items in the taskbar like MS…
sohum
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1 answer
Applying Hann windowing function to an image in Octave/Matlab
If i understand the concept correctly, we apply a windowing function to the FFT of a signal to eliminate unwanted frequencies/noise.
How does one apply it to images since they are 2D matrices?
img = imread('file.png');
w = hann(512);
y =…
sqram
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1 answer
Better way to rewrite windowing function
Production table have more than 32 M records, for testing purpose created synthetic tab which have 6M records. The below query is taking more than 10 min and killed the process in middle.
Any suggestion, how can we optimize below query.
select
…
Learn Hadoop
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2 answers
how can I get the last value for each key in a set of postgres hstore records?
I have a table of sensor readings as postgres hstore key-value pairs.
Each record has a timestamp at 1 sec intervals.
Not all sensors record every second.
The table is essentially:
create table readings (
timer timestamp primary key,
…
Brent Wood
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1 answer
SQL Window function, count the number of events in a 180 day window using each event date as an index
I need to be able to find the minimum date out of a set of dates that fit the following criteria.
3 dates which are within 180 days of each other. The logic which i'm guessing would apply is that each date would be an index from which subsequent…
SQL_Novice
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1 answer
SQL finding total flagged hours within first 8 hours worked
I am aiming to find total hours worked in a day for shifts or fractions of shifts per person that are tagged with a value and fall within the first 8 hours of work, excluding breaks, on any day. Then display tagged shifts along with eligible total…
Billy
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How to find the next occurring item from current row in a data frame using Spark Windowing?
I have the following Dataframe:
+------+----------+-------------+--------------------+---------+-----+----------+
|ID |MEM_ID | BFS | SVC_DT |TYP |SEQ |BFS_SEQ …
Premkumar
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1 answer
Hive Windowing ORDER BY
Hello I am very new to Hive and was learning WINDOWING functionality of Hive. I came across a problem.
I was trying to find the lowest closing price for each stock ticker (Each ticker have 22 records and I wanted to find the lowest)
I wrote a…
Dereck
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1 answer
Hann window starts and ends with values that don't seem to make sense
I am playing around with mathdotnet and am experimenting with the different windows for use in FFTs. I am specifically curious about the Hann window (though i'm sure this applies to the others as well). When I generate a Hann window of, say, 2048…
Matthew Goulart
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2 answers
R - Fast way to calculate rolling mean with varying width
I have a dataframe that contains bank assets for several dates (times). Each bank has a unique ID:
# Sample Data
time <- c(51, 52, 53, 55, 56, 51, 52, 51, 52, 53)
id <- c(1234, 1234, 1234, 1234, 1234, 2345, 2345, 3456, 3456, 3456)
name <- c("BANK…
jb123
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1 answer
Windowing function: Finding max value from LAG()
I'm currently working my way through the exam study book, Querying Microsoft SQL Server 2012. I've been learning SQL over the last few months and I am currently looking over windowing functions. I came to this application question and it got me…
Walker
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how to get coeefficient bandpass FIR Filter Design with Python
I'm trying to make a DSP with python, I am a beginner, like this site https://mbed.org/cookbook/FIR-Filte
1. I look for coefficients with python, but how to find the coefficient FIR bandpass using hamming window, can you give me an example?
2. how…
user9131
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1 answer
How to find the difference between 1st row and nth row of a dataframe based on a condition using Spark Windowing
Here is my exact requirement. I have to add a new column named ("DAYS_TO_NEXT_PD_ENCOUNTER"). As the name indicates, the values in the new column should have a difference of RANK that has claim_typ as 'PD' and the current row. For one ID, it can…
Premkumar
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1 answer
Cannot use the "over" clause with MySQL workbench 8.0 (MySQL version 5.7.31)
I struggle to see what I'm doing wrong. I have noticed that some syntax doesn't work (I've had this issue with the keywords "WITH" and now with "OVER".
I am applying a windowing function on a table with the columns id, price and cluster. I want to…
ml_chai
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