FAQ Database Discussion Community

## getting fitted lines with scatterplot matrix in r

r,regression,linear
How do I get a scatterplot matrix which will also show the fitted lines in each plot. I know how to use "abline" function with individual plots but don't know how to implement it in a scatterplot matrix

## Constrained high order polynomial regression

matlab,regression
I am doing some bone segmentation whereas the result of this segmentation is points placed in a circular pattern around this bone. However as it is taken using a qCT scan, there is quite a lot noise (from e.g. flesh) on the points that i have. So the overall problem...

## Stata — predict after regression by group_id

regression,stata,predict
I have to run regressions by group_id and then generate the predictions. It doesn't seem like predict allows the "by" option. Is there a way I can predict after running regressions by group_id? The data are stacked by group_id. The regression command I am thinking of using is as follows:...

## Java 8 change in UTF-8 decoding

java,utf-8,java-8,regression
We recently migrated our application to JDK 8 from JDK 7. After the change, we ran into a problem with the following snippet of code. String output = new String(byteArray, "UTF-8"); The byte array may contain invalid UTF-8 byte sequences. The same byte array upon UTF-8 decoding, results in two...

## An error while looping a linear regression

r,loops,data.frame,regression
I would like to run a loop that will run per each category of one of the variables and produce a prediction per each regression so that the sum of the prediction variable will be deduced from the target variable .Here Is my toy data and code: df <- read.table(text...

## Tidy approach to regression models, ideally with dplyr

r,regression,dplyr,lm
Reading the documentation for do() in dplyr, I've been impressed by the ability to create regression models for groups of data and was wondering whether it would be possible to replicate it using different independent variables rather than groups of data. So far I've tried require(dplyr) data(mtcars) models <- data.frame(var...

## How to plot a scatter plot with error bars indicating standard deviation

matlab,statistics,regression
I have a set of data Y v/s X (~20k data points) which when plotted are a scatter. I want to plot error bars for Y for a ranges of X(eg. the X axis is of length 100, then I want the errorbars to represent the standard deviation of Y...

## Determining regression coefficients for data - MATLAB

matlab,matrix,regression,numerical-methods
I am doing a project involving scientific computing. The following are three variables and their values I got after some experiments. There is also an equation with three unknowns, a, b and c: x=(a+0.98)/y+(b+0.7)/z+c How do I get values of a,b,c using the above? Is this possible in MATLAB?...

## Partition dataset using CART regression by leaf node

r,regression
I'm currently trying to modify an existing Stata model in R, and I'm running into problems with a specific step in the process. I need to use a CART regression to divide my dataset up into individual clusters based on their leaf node, such that each leaf node becomes a...

## Plotting a independent variable under a parameter of another variable in R

r,plot,regression
I have a function predictshrine<-0*rain-399.8993+5*crops+50.4296*log(citysize)+ 4.5071*wonders*chief+.02301*children*deaths+1.806*children+ .10799*deaths-2.0755*wonders-.0878*children^2+.001062*children^3- .000004288*children^4-.009*deaths^2+.0000530238*deaths^3+ 7.974*sqrt(children)+.026937*wonders^2-.0001305*wonders^3 I also have a sequence children<-seq(0,100,length=500) And a for loop for(deaths in c(0,5,10,50,100,200)) Now what i want to do is be able to plot predictshrine vs children when deaths equals certain amounts and...

## R: HAC by NeweyWest using dynlm

r,time-series,regression

## Loop through various data subsets in lm() in R

r,loops,regression,subset

## R— repeating linear regression in a large dataset

r,regression
I'm an R newbie working with an annual time series dataset (named "timeseries"). The set has one column for year and another 600 columns with the yearly values for different locations ("L1," "L2", etc), e.g. similar to the following: Year L1 L2 L3 L4 1963 0.63 0.23 1.33 1.41 1964...

## How to fit an elliptic cone to a set of data?

matlab,regression,curve-fitting,ellipse,best-fit-curve
I have a set of 3d data (300 points) that create a surface which looks like two cones or ellipsoids connected to each other. I want a way to find the equation of a best fit ellipsoid or cone to this dataset. The regression method is not important, the easier...

## Getting coefficient at best lambda in glmnet in R

r,lambda,regression,glmnet

## Regression loop in R for data frames

r,loops,statistics,data.frame,regression
rm(list=ls()) myData <-read.csv(file="C:/Users/Documents/myfile.csv",header=TRUE, sep=",") for(i in names(myData)) { colNum <- grep(i,colnames(myData)) ##asigns a value to each column if(is.numeric(myData[3,colNum])) ##if row 3 is numeric, the entire column is { ##print(nxeData[,i]) fit <- lm(myData[,i] ~ etch_source_Avg, data=myData) #does a regression for each column in my csv file against my independent variable 'etch'...

## Regression gives error on one of the input variables “contrasts can be applied only to factors with 2 or more levels”

r,regression,categorical-data
I am running a logit regression in R with a large number of input variables. newlogit <- glm(install. ~ SIZES + GROSSCONSUMPTION.... + NETTCONSUMPTION..... + NETTGENERATION....... + GROSSGENERATION.... + Variable. + Fixed + Cost.of.gross.cons + Cost.of.net.cons + Cons.savings + generation.gains + Total.savings + Cost.of.system + Payback + Self.consumption + Total.consumption.as.solar...

## Python stats.linregress syntax error

python,syntax,regression,linear
I am trying to calculate the regression of the x and y variables, trace_no and twwt, respectively. The variable are 151 x 1 arrays. The code is outputting a syntax error: File "./seabed_dip_correction.py", line 32 slope, intercept, r_value, p_value, std_err, Syy/Sxx = stats.linregress(trace_no,twtt) SyntaxError: can't assign to operator I have...

## Input format for functions in package strucchange?

r,regression,trend
I'm trying to do change point detection with ´monitor´ from the strucchange package, but I have trouble getting a useful output. My input is a time stamped dataframe, and I would like the breaks to be returned as dates, but they are returned as observation number: cDF1 <- myDF[1:80,] >...

## How to make a for loop to find interactions between several variables in R?

r,regression,linear
I have a data set with 17 variables the data is available at this link http://www.uwyo.edu/crawford/stat3050/final%20project/maxwellchandler.txt I want to find significant interactions between the variables. For example fitcivilian<-lm(Civilian~Stock+Terrorism+log(Firepower)+Payload+Bombs*Temperature+FirstAid+Spies+Personnel+IG88, data=data) where Bombs*Temperature is significant What I want to do is test EVERY varaible against EVERY OTHER variable, Like doing Bombs*Temperature Bombs*Napalm...

## How to find fourth and fifth regression coefficients in R?

r,regression
I would like to compute 5 regression coefficients.I searched thru Internet but I did not find anything for this. my data: y=c(2,13,0.4,5,8,10,13) x=c(2,13,0.004,5,8,1,13) z=c(2,3,0.004,15,8,10,1) normal equation: y=a1x+a2z+a3 x, z, independent variables, y is the dependent variable, and a1 a3, and a2 are the parameters of the model. normal fit for...

## Used Predict function on New Dataset with different Columns

r,regression,predict
Using "stackloss" data in R, I created a regression model as seen below: stackloss.lm = lm(stack.loss ~ Air.Flow + Water.Temp + Acid.Conc.,data=stackloss) stackloss.lm newdata = data.frame(Air.Flow=stackloss$Air.Flow, Water.Temp= stackloss$Water.Temp, Acid.Conc.=stackloss\$Acid.Conc.) Suppose I get a new data set and would need predict its "stack.loss" based on the previous model as seen below:...