Selecting particular columns from large datasets (csv) using R Studio?

So I have large number of csv files (100+) in a directory with same structure and column names. The data is in time series and there are approx 30 columns/file. However i only want to aggregate...

08 February 2021 245 5 View

Is it necessary to include orbital dynamics (translational) in attitude dynamics (rotational) problem?

I want to simulate satellite attitude control with a quaternion attitude representation. thrusters and reaction wheels are the main AOCS controllers. is it Ok to omit orbit dynamics (orbit...

31 January 2021 5,094 2 View

How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for Metabarcoding?

I'm working on pollen DNA metabarcoding to identify the floral composition of honey. How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for the...

28 December 2020 9,132 1 View

How to add two vertical and parallel Fresnel reflection coefficients to retrieve overall reflection coefficient for a right hand circular wave?

I have a problem in which a right hand circular polarized wave (GPS wave) encounters an ideal smooth plane obliquely, and then is reflected off that. To solve this kind of problems, the wave is...

28 December 2020 2,271 3 View

Which is better to focus on teaching or research for a good academic life and Why?

Which is better to focus on teaching or research for For a good academic life and Why?

26 December 2020 5,737 9 View

Is ag paste suitable for back contact on silicon wafer? or i should deposit al on the back surface using pvd or plasma sputtering?

Fabricating silicon solar cell

22 December 2020 4,906 7 View

Which renewable source is the best ?

wind hydro solar etc.

21 December 2020 6,360 16 View

Why is light pure energy?

light is pure because the light is the simplest electromagnetic construct but the energy of any object is also of the same kind.

20 December 2020 207 4 View

How to handle Missing Values for Skipped Questions (Systematic Missing) in R ?

10 December 2020 435 4 View

What is the best industrial emulsifier to make silicon oil in water emulsion?

I need to make long-lasting stable emulsions of 6 wt. % percent silicon oil in DI water. The previousely made emulsions using Tween and Span Emulsifiers did not remain stable after a week.

31 October 2020 3,568 3 View

Binary Logistic Generalized Linear Mixed model in SPSS. Is it doable?

I want to analyses the proportion of swimming sperm of three species of fish in two salinities. To analyse the proportion of swimming sperm in a Generalized Linear Model, I would use a Binary...

03 March 2021 2,297 3 View

Dear all, I was wondering if anyone knows whether MGLtools and Autodock can run on Mac OS?

I have tried to download the 64-bit version of MGLtools however, as many times as I have downloaded and uninstall the programs, an error arises that the app needs to be updated. Thank you.

03 March 2021 5,997 2 View

What test should i use in comparing the correlation between categorical and continuous variables?

Dear all, I have the variable (Surgery duration) represented by values in minutes and the variable (preoperative neuropraxia cases) represented as (Yes/No) values. I want to compare these two...

03 March 2021 5,427 5 View

Logistical regression using SPSS for a dichotomous dependent variable, with an independent variable of 1, 2, 5 and 10 seconds?

I have an experiment with 28 participants The independent variable is the times 1, 2, 5, and 10 used as the cross hairs during a task These 4 times were tested using 4 different blocks, each...

03 March 2021 9,692 2 View

How to find the mean, SD and CI in SPSS?

Hi, I hope that someone can help me with this task: I have 5 groups of participants which are numbered in SPSS from 1 to 5 (according to their group number) and are all under the variable group....

03 March 2021 506 3 View

What degree of missing data in a particular case/participant results in Expectation-Maximisation no longer working?

I'm dealing with a mediation model and am using the PROCESS module in SPSS. Due to SPSS and PROCESS being limited in the imputation methods - being unable to handle multiple imputation - the other...

02 March 2021 4,362 1 View

How to code open-ended questions in SPSS?

Hello all, In SPSS I am going to code 2 open-ended questions. I have already read all the answers and I made a list of the most important categories to which I can code the answers. This question...

02 March 2021 1,757 4 View

The procedure compute?

02 March 2021 5,204 3 View

Does anyone know what a '.' means in SPSS?

Hi everyone! I was wondering if anyone would be so kind as to help me with regards to my data set on SPSS! I was checking for multivariate outliers via the standardised residuals ('Linear...

02 March 2021 7,910 3 View

How to calculate BREQ 3 questionnaire?

how to calculate BEHAVIOURAL REGULATION IN EXERCISE QUESTIONNAIRE BREQ 3 ,which contain 24 questions and each question has 5 answers (0- Strongly disagree , 1-disagree, 2- Neither agree nor...

02 March 2021 811 3 View