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Questions tagged [threshold]

The starting point for a new state.

715 questions
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EmguCV - Canny function throwing _src.depth()==CV_8U

I'm working currently on a project where I use EmguCV 4.2 I need to use Canny function: gray=gray.Canny(50, 200); And it's throwing error: _src.depth()==CV_8U I noticed that exception occurs only if I use CvInvoke.Threshold() on my image…
shefff
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Efficient threshold checks of absolute value in embedded C

I thinking about a efficient way of implementing a threshold check (with optional hysteresis and delay). Requirement/situation: I want to check e.g. an non-negative value (e.g. absolute pressure) against an upper threshold and an lower threshold…
ElvisIsAlive
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Compute Youden index from two density plot

I need help with calculating the Youden index in a two density plot in R. Basically, I need to calculate the value where two density plots are overlapping The variables are numeric. Is there any method for calculating this value (Youden index) ???
J.R.
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How to threshold vectors [u,v] in a 2D numpy array?

I wrote a threshold function TH(arr, threshold) that takes in a 2D array of vectors [u,v], and sets u and v to 0 if they both have an absolute value lower than a specified threshold. The function consists of 2 for-loops and does the job, but is…
Honey Gourami
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how to calculate Otsu threshold in 1D

I'm trying to identify bimodal distributions in my analytical chemistry data. Each data set is a list of 3~70 retention times for a particular compound from the GC-MS. RTs for some compound are bimodally distributed where the library searches have…
Ninja Chris
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Find the first index for which an array goes below a certain threshold (and stay below for some time)

Let A be a 1D numpy array, a threshold t, and a window length K. How to find the minimal index j, such that A[j:j+K] < t? (i.e. the first time A stays below the threshold on a full window of width K). I've tried (unfinished) things with a loop, but…
Basj
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R - Threshold linear regression model

I am looking for a package in R containing a threshold regression model or a threshold autoregressive (ar) model with extra exogenous explonatary variables for time series? By now I came across following packages, which do not fully capture the…
krson
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computing onset date of snowmelt in R

I have daily temperature in this format starting from 1950 to 2017 Data I need to compute snowmelt onset date which is defined as as the the first day when daily temperature is above 0 C, following the last five-day period between March and May,…
nee
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Iterate over a tensor's rows and cols in Tensorflow

A part of my project is to use a thresholding kernel on an image. The thresholding kernel could look like this: [50 100] [150 200] I would like to go over each group of 3x3 pixels (without overlap), and threshold them using my kernel. For…
Ori Linial
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set threshold for the probability result from decision tree

I tried to calculate the confusion matrix after I conduct the decision tree model # tree model tree <- rpart(LoanStatus_B ~.,data=train, method='class') # confusion matrix pdata <- predict(tree, newdata = test, type = "class") confusionMatrix(data =…
Pumpkin C
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Exclude rows surpassing threshold value

I have a dataset df field_pointpath assetclass_code value C_THDxL_0154x6KSFS_A03x6KSF_11xaP_ACT 6KSFS_6KSF 50 C_THDxL_0154x6KSFS_A03x6KSF_11xaP_ACT 6KSFS_6KSF 60 C_THDxL_0154x6KSFS_A03x6KSF_11xaP_ACT …
user3301082
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Cumulative Monthly YTD Based on Threshold

I am trying to create a cumulative monthly ytd calculation where based on a threshold a 'player' is only counted towards the numerator & denominator once (as soon as they have a recorded score) and can move into the "met threshold" group and then…
AVD
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SharePoint 2010 - List view threshold: What does not trigger the threshold?

In SharePoint 2010, we have the List View Threshold, which defaults to 5,000, and: Specifies the maximum number of list or library items that a database operation, such as a query, can process at the same time outside the daily time window set by…
9b5b
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RabbitMQ , .NET and multithreading

I've been playing with RabbitMQ and its .NET connector for a while. After a period under test, my new system using RabbitMQ as a broker in a network of web applications and API, hit production. All the apps got stuck in a matter of minutes. I…
Ph user
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Filter/subset dataframe to threshold of change

I have the following dataframe containing values for angular change in degree, over multiple rows: 'data.frame': 712801 obs. of 4 variables: $ time_passed: int 1 2 3 4 5 6 7 8 9 10 ... $ dRoll : num 0.9798 -0.5099 -0.0974 -0.4985 0.1719…
Joris
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