Can someone indicate a real life example on how to process an xgb.DMatrix for a regular data file (for xgboost package in R) ?

Hi, I tried processing data in order to get an xgb.DMatrix object, but I ran into difficulties. All examples found in the xgboost package documentation or Xgboost presentation vignette are...

07 August 2018 2,679 6 View

Can anyone give examples of cross-sectional data that exhibits autocorrelation other than spatial data?

I'm looking for examples and analyses of autocorrelation tests performed on cross-sectional data and the issues encountered (data prop for analysis, problems with estimations, etc). Not interested...

01 February 2016 3,932 2 View

Can anyone direct me to this paper by Noether (1963) A note on the Kolmogorov-Smirnov statistic in the discrete case?

31 December 2015 7,680 5 View

What is your favorite reference econometrics book?

Except for econometricians, most of us usually have one or more books they refer to when we want to get a first-hand reference on some basic or advanced topics, and/or get some basic understanding...

31 December 2013 2,780 5 View

Are there any data-processing routines-scripts available for R?

I need to process some data, nothing fancy, crosstabs, means and medians, and I want to automate it as much as possible. So far I use xtabs and SummaryBy from the doBy library. Do you know if...

04 May 2013 1,907 1 View

Data Science International Summer School, 17-26 July 2020 Predeal, Romania

01 January 1970 2,332 2 View

Anyone plz suggest relevant topic for research in image processing+Deep learning.?

I have selected brain tumor images ...but now found that already lots of research done n this topic.

03 March 2021 5,774 3 View

Can we block unwanted images during the x-ray prediction?

i am try to classify the x-ray images. During classification , can i block unwanted images (except x-ray image).

03 March 2021 7,100 1 View

I need to image mesoporous silica nanoparticles that are in ~100 nm size and do high resolution TEM to look at mesopores. what grids should I use?

Need to image mesoporous silica nanoparticles using the TEM. Also, need high resolution TEM images to see the mesoporous structure. Kindly suggest what kind of grids to use. Thanks, Shatadru

02 March 2021 1,787 2 View

How to normalise data on OPM package from R Studio ?

Good afternoon, I recently used OmniLog from BIOLOG for my experimentations : I tested the metabolism of different strains on 2 types of plates. I have 16 strains of 3 different groups...

02 March 2021 3,584 1 View

Do I need to strip the PVDF membrane before staining it with colloidal gold?

Dear Colleagues, After running Western blot on PVDF membrane and detection using ECL, I would like to stain my PVDF with colloidal gold to be able to allign the ECL image with total proteins on...

02 March 2021 7,829 3 View

Do you know any MR image dataset?

I would like to research on MR images (0.5T and 3T). Can you please suggest some websites that I can download dataset including both 0.5T and 3T MR images? Thank you.

02 March 2021 7,735 3 View

How to find the mode of classified ocean colour images?

Hello, I have classified 10 S3 OLCI images from the same area (althouth not the same size and/or quadrant) and I would like to do a final image using the mode of the pixel of these 10 images. I...

01 March 2021 9,874 3 View

How to threshold an image despite bright lighting, using ImageJ/Fiji?

Hi everyone, I am using Fiji to determine the percentage of the image covered by leaves, branches, or trunk, but i've encountered some difficulty when the sun hits parts of my image like the one...

27 February 2021 1,194 3 View

Trouble with Charting with Google Earth Engine (Technical)?

Hello. I have a problem with the charting in google earth engine. I created an image collection by combining 5 image collections of five parameters and using ee.Join.inner ( ) and .apply ( )...

26 February 2021 7,084 2 View

How to plot the probability paper of Gumbel distribution using R programing?

In R-studio, there are many commands of Gumbel package. Arguments are also different. I`m asking about the alpha parameter of the Copula which must be greater than 1. If this is the one used to...

25 February 2021 5,229 3 View