Viewshed analysis in R: any package available?

I am wondering if there is any package in R containing function(s) to perform viewshed analysis. I am not interested in packages that need the underlying presence of ArcGIS or GRASS; I am looking...

01 February 2018 9,947 4 View

How to locate in GIS large pits or depressions deeper than the surrounding ground by a given value?

As per title, I was wondering how in a DEM (i.e., a bare-earth DEM) one can locate depressions that are deeper than the surrounding ground by at least a given value. The main issue is that, quite...

09 October 2017 5,232 9 View

How to interpolate wind direction in GIS using transformation?

Hello. I have a point shapefile representing the location of weather stations; for each point, the wind speed and wind direction (in degrees) is recorded. I need to create a cotninous surface...

03 April 2017 653 9 View

How to meaningfully incorporate wind direction into the calculation of least-cost paths for navigation (ArcGIS)?

02 March 2017 4,112 3 View

Slope in degree or percent when implementing Tobler's hiking function in GIS?

Hello All, as per title, I am rather confused as to using slope raster in degree or percent when implementing Tobler function in GIS. Some sources (A, B, C) seem to point to slope degree, while...

31 December 2016 346 23 View

Any available worked example for QGIS r.walk module?

11 December 2016 7,368 5 View

How we can calculate the average leverage when one predictor is categorical?

In Logistic Regression (as in regression in general), when it comes to check model's diagnostics, one has to check for observations with higher-than-average leverage. From what I read in several...

08 September 2016 2,689 3 View

Does anyone know about possible function of ceramic disks from prehistoric contexts?

I was wondering if anyone has ever come across ceramic disks from prehistoric contexts, huts in particular. By ceramic disks I mean sherds from pots' wall, reworked in such a way to eventually...

04 May 2016 9,132 26 View

Does anyone know any free tools to rectify images?

I have a aerial photo which is slightly oblique. I would like to use a free program capable to rectify images; this should be a preliminary step toward georeferencing the picture. Many months ago,...

02 March 2016 8,821 7 View

'cvAUC' R package: how do I format input data?

Hello, I was wondering if anyone could shed light on an issue I am experiencing with the package cvAUC (link provided below). I wish to get the function cvAUC to work, yet I am not getting the...

11 December 2015 4,699 4 View

How to compare two groups with only two measurements?

Hiiiii everyone! I have an enquiry on statistical analysis. I was looking for many forum and it's still cannot solve my problem. I want to compare means of two groups of data but only with two...

03 March 2021 8,796 3 View

Can we classify HV and LV lines based on line length?

I have dataset which shows the length of power lines. I need to classify the lines based on the line length. Is there a rule to classify the High voltage (HV) and low voltage (LV) lines based on...

03 March 2021 4,116 4 View

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

Irradiation data for JAPAN?

Hi, Could you help me to get the latest (2019, 2020) solar resource data for a particular site in JAPAN? PV GIS and NSRDB data are not in reach to JAPAN, I'm looking for some other database for...

03 March 2021 961 3 View

How to increase a model accuracy ?

dear community, my model is based feature extraction from non stationary signals using discrete Wavelet Transform and then using statistical features then machine learning classifiers in order to...

03 March 2021 6,994 5 View

1. What is the impact of having different scales in a survey? and how can we solve this problem before and after data collection (Literature)?

1. What is the impact of having different scales in a survey? and how can we solve this problem before and after data collection (Literature-based reflection)? Thank you for your time and for...

03 March 2021 2,870 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 calculate average trend in maximum annual NDVI from MODIS?

I am wanting to calculate the average trend in maximum annual NDVI in Iceland from 2010-2020 using MODIS MYD13Q1 V6. How would I do this? I have currently inserted the NDVI bands from the MODIS...

02 March 2021 752 2 View

Can you share me how teacher education is managed in your respective national educational system?

I feel that the practice in teacher education in my country is below the expected performance level due to very poor management system. Hope I will learn something from your experiences.

02 March 2021 1,516 4 View

Can NFL theorem be valid in infinite search space in ML?

NFL theorem is valid for algorithms training in fixed training set. However, the general characteristic of algorithms in expanded or open dataset has not been proved yet. Could you show your...

01 March 2021 1,189 3 View