pass parameters in GSL integration

struct my_f_params {int a; int b;}; 
gsl_function F1; 
struct my_f_params alpha = {2,2};               
F1.function = &f1; 
F1.params = & alpha;

struct my_f_params * params = (struct my_f_params *)p;
int n = (params->a);
int m = (params->b);

----------

double params[] = { y, z };
F.params = params;

double y = ((double *)params)[0];
double z =  *((double *)p+1);

Levi-Civita symbol and cross product

 

Reference:

http://www.homepages.ucl.ac.uk/~ucappgu/seminars/levi-civita.pdf

https://en.wikipedia.org/wiki/Levi-Civita_symbol

Tools

EPIC implements exponential integrators that can be used to solve large stiff systems of differential equations

https://www.oacommunity.org/resources

// resources related to academic writing 

Resources: applying for PhD / Postdoc / Faculty and more

save website as pdf https://pdfmage.org/

Alfven speed

 

combine/delete/rotate pdf in linux

There are two very useful open-source tools.

pdfarranger

pdfmixtool

citation map

https://jokergoo.github.io/2023/02/18/generate-citation-map/

library(V8)

ct = v8()

ct$source("~/citation.json")

citation = ct$get("citation")

results = citation$results[, 1:4] head(results)

tb = data.frame(address = tapply(results$address, results$address, function(x) x[1]), publicationCount = tapply(results$publicationCount, results$address, sum), lat = tapply(results$lat, results$address, mean), lon = tapply(results$lon, results$address, mean))

library("sf") library("rnaturalearth") library("rnaturalearthdata") world = ne_countries(scale = "medium", returnclass = "sf") library(ggplot2) library(ggrepel) library(RColorBrewer) ggplot(data = world) + geom_sf(color = "grey", fill = NA) + geom_point(data = tb[order(tb$publicationCount), ], aes(x = lon, y = lat, color = publicationCount, size = publicationCount)) + scale_colour_gradientn(colours = rev(brewer.pal(9, "Spectral"))) + scale_size(range = c(0.2, 3)) + geom_text_repel(data = tb[order(-tb$publicationCount)[1:20], ], mapping = aes(x = lon, y = lat, label = gsub(", .*$", "", address)), box.padding = 0.5, max.overlaps = Inf, min.segment.length = 0, size = 3)

https://guides.library.harvard.edu/c.php?g=311134&p=4423814