Sorry guys in advance if my question is trivial but I am new to R.
when I try to run the following chunk, the curves is plotted but I get the warning :'add' will be ignored as there is no existing plot.
and if I try to knit the whole document, it is interrupted with the following error: Error in plot.xy(xy.coords(x,y), type=type, ...) plot.new has not been called yet
library(pwr)
occ <- function(type, conf.level=0.05) {
n_levels <- c(2, 3, 4, 5, 10, 20, 50, 100)
ty <- 0.8
for (i in n_levels) {
curve(1-pwr.t.test(i, x, type=type, sig.level=conf.level)$power, add=T,
xlim=c(0,6),
ylim=c(0,1),
xlab="d",
ylab="P(Tpe II error) or (1- Power)",
main="Operative Characteristic curves for two samples T-test")
tx <- pwr.t.test(i, power=1- ty, type=type, sig.level=conf.level)$d
text(tx, ty, lab=i, col="red")
ty <- ty - 0.1
}
}
occ("two.sample", 0.01)
I have a CSV file that look something like below: i.e. not in Prolog format
james,facebook,intel,samsung
rebecca,intel,samsung,facebook
Ian,samsung,facebook,intel
I am trying to write a Prolog predicate that reads the file and returns a list that looks like
[[james,facebook,intel,samsung],[rebecca,intel,samsung,facebook],[Ian,samsung,facebook,intel]]
to be used further in other predicates.
I am still a beginner and have found some good information from SO and modified them to see if I can get it but I`m stuck because I only generate a list that looks like this
[[(james,facebook,intel,samsung)],[(rebecca,intel,samsung,facebook)],[(Ian,samsung,facebook,intel)]]
which means when I call the head of the inner lists I get (james,facebook,intel,samsung) and not james.
Here is the code being used :- (seen on SO and modified)
stream_representations(Input,Lines) :-
read_line_to_codes(Input,Line),
( Line == end_of_file
-> Lines = []
; atom_codes(FinalLine, Line),
term_to_atom(LineTerm,FinalLine),
Lines = [[LineTerm] | FurtherLines],
stream_representations(Input,FurtherLines)
).
main(Lines) :-
open('file.txt', read, Input),
stream_representations(Input, Lines),
close(Input).
The problem lies with term_to_atom(LineTerm,FinalLine).
First we read a line of the CSV file into a list of character codes in
read_line_to_codes(Input,Line).
Let's simulate input with atom_codes/2:
?- atom_codes('james,facebook,intel,samsung',Line).
Line = [106, 97, 109, 101, 115, 44, 102, 97, 99|...].
Then we recompose the original atom read in into FinalLine (this seems wasteful, there must be a way to hoover up a line into an atom directly)
?- atom_codes('james,facebook,intel,samsung',Line),
atom_codes(FinalLine, Line).
Line = [106, 97, 109, 101, 115, 44, 102, 97, 99|...],
FinalLine = 'james,facebook,intel,samsung'.
The we try to map this atom in FinalLine into a term, LineTerm, using term_to_atom/2
?- atom_codes('james,facebook,intel,samsung',Line),
atom_codes(FinalLine, Line),
term_to_atom(LineTerm,FinalLine).
Line = [106, 97, 109, 101, 115, 44, 102, 97, 99|...],
FinalLine = 'james,facebook,intel,samsung',
LineTerm = (james, facebook, intel, samsung).
You see the problem here: LineTerm is not quite a list, but a nested term using the functor , to separate elements:
?- atom_codes('james,facebook,intel,samsung',Line),
atom_codes(FinalLine, Line),
term_to_atom(LineTerm,FinalLine),
write_canonical(LineTerm).
','(james,','(facebook,','(intel,samsung)))
Line = [106, 97, 109, 101, 115, 44, 102, 97, 99|...],
FinalLine = 'james,facebook,intel,samsung',
LineTerm = (james, facebook, intel, samsung).
This ','(james,','(facebook,','(intel,samsung))) term will thus also be in the final result, just written differently: (james,facebook,intel,samsung) and packed into a list:
[(james,facebook,intel,samsung)]
You do not want this term, you want a list. You could use atomic_list_concat/2 to create a new atom that can be read as a list:
?- atom_codes('james,facebook,intel,samsung',Line),
atom_codes(FinalLine, Line),
atomic_list_concat(['[',FinalLine,']'],ListyAtom),
term_to_atom(LineTerm,ListyAtom),
LineTerm = [V1,V2,V3,V4].
Line = [106, 97, 109, 101, 115, 44, 102, 97, 99|...],
FinalLine = 'james,facebook,intel,samsung',
ListyAtom = '[james,facebook,intel,samsung]',
LineTerm = [james, facebook, intel, samsung],
V1 = james,
V2 = facebook,
V3 = intel,
V4 = samsung.
But that's rather barbaric.
We must do this whole processing in fewer steps:
Read a line of comma-separated strings on input.
Transform this into a list of either atoms or strings directly.
DCGs seem like the correct solution. Maybe someone can add a two-liner.
I have a large set of .tif files and I need to merge/mosaic them all into one .tif with the no-data value removed (i.e. value 230, 245, 255).
However, when I put this in...pixel '230, 245, 255' becomes '0, 245, 255').
I am trying to get NO PIXEL returned for 230, 245, 255. Is that possible?
I:\TFS_6\trial_merge>gdal_merge.py -o test.tif -n 230 245 255 file1.tif file2.tif
ERROR 4: `245' does not exist in the file system,
and is not recognised as a supported dataset name.
ERROR 4: `255' does not exist in the file system,
and is not recognised as a supported dataset name.
0...10...20...30...40...50...60...70...80...90...100 - done.
gdalbuildvrt -addalpha -hidenodata -srcnodata "230 245 255" merged_tif.vrt *.tif
This turned the 'NoData' values into '230 245 255'...so I was able to filter BOTH 'NoData' and '230 245 255' accordingly,
I have an N x 2 table of integers called games[ , ]. The table of nodes/edges is converted to a graph:
net <- graph.data.frame(as.data.frame(games), directed=FALSE)
deg.net <- degree(net, mode='total', loops=FALSE)
(I realize that not all options are necessary.)
The problem I am having is that the degree distribution seems to be for in-degree only. For example, the games file has the lines:
103 86
24 103
103 2
92 103
87 103
103 101
103 44
and yet igraph indicates that the degree for node 103 is '3' when it should be '7'.
Any insight in what I am missing would be appreciated.
One thing that you should keep in mind is that most igraph functions refer to the vertices by their IDs, which are simply integers from 0 to N-1 where N is the number of vertices in the graph. If you have an N x 2 table of integers (containing zero-based vertex indices) and you want igraph to use the integers as the vertex IDs, you can simply use the graph constructor after having flattened the matrix into a vector by rows. When you use graph.data.frame, the first two columns of the data frame are assumed to contain symbolic vertex names (i.e. there is no requirement that they must be integers); these will be assigned to the name vertex attribute, and igraph will simply make up the IDs from 0 to N-1.
So, let's assume that you have an N x 2 matrix, one row per each edge:
> edges <- matrix(c(103, 86, 24, 103, 103, 2, 92, 103, 87, 103, 103, 101, 103, 44), ncol=2, byrow=T)
First we create a graph out of it after flattening the matrix by rows:
> g <- graph(as.vector(t(edges)))
This gives you a directed graph with 7 edges and the out/in-degrees of vertex 103 will be as expected:
> ecount(g)
7
> degree(g, 103, mode="out")
4
> degree(g, 103, mode="in")
3
> degree(g, 103, mode="all")
7
If you use graph.data.frame with the above matrix, igraph will construct a graph where the numbers in the matrix are stored in the name vertex attribute:
> g <- graph.data.frame(as.data.frame(edges))
> V(g)$name
[1] "103" "24" "92" "87" "86" "2" "101" "44"
This shows you that the vertex with the name 103 actually became vertex zero in the graph:
> degree(g, 0, mode="out")
4
> degree(g, 0, mode="in")
3
> degree(g, 0, mode="all")
7
As far as I know, degree is also able to work with the vertex names directly if there is a vertex attribute called name in the graph, so you can also do this:
> degree(g, "103", mode="in")
3
Hope this helps.
You created a undirected graph. There is no in and out degree in such a graph. From the igraph documentation link you can get the general idea. Your deg.net will return a vector with all the degrees(per node) on your graph, similar to this:
[1] 2 1 1 1 1 1 1
If you want to get the degree of a specific node(in our example it's 103) you have to specify the node(appearence_order-1). In your example you are looking for the (1st_node-1), it's node 0. So you must type:
degree(net,0, mode='total', loops=FALSE)
Which will return the degree of node 0, "7".
I'm trying to manually (no libs such as Three.js) load a JSON 3D model into my webGL code just for fun but I'm having a hard time when my models have more than 1 texture.
In a OBJ->JSON converted file, how do I know which texture is the "active" for the faces that follow? OBJ files use 'usemtl' tag to identify the texture/material in use but I can't seem to find that kind of pointer when working with JSONs.
In time, I'm using the OBJ->JSON converter written by alteredq
Thanks a bunch,
Rod
Take a look at this file: three.js / src / extras / loaders / JSONLoader.js.
The first element of each face in the faces array of the JSON file is a bit field. The first bit says if that face have three o four indices. And the second bit says if that face has a material assigned. Material index, if any, appears after indices.
Example: faces: [2, 46, 44, 42, 0, 1, 45, 46, 48, 3, ...
First face (triangle with material):
Type: 2 (00000010b)
Indices: 46, 44, 42
Material index: 0
Second face (quad without material):
Type: 1 (00000001b)
Indices: 45, 46, 48
Third face (quad with material):
Type: 3 (00000011b)
Indices: ...
Check source code for full meaning of that bit field.
In the OBJ->JSON converter I have written for the KickJS game engine, each material has its own range of indices.
This means a simple OBJ model such as
mtllib plane.mtl
o Plane
v 1.000000 0.000000 -1.000000
v 1.000000 0.000000 1.000000
v -1.000000 0.000000 1.000000
v -1.000000 0.000000 -1.000000
usemtl Material
s 1
f 2 3 4
usemtl Material.001
f 1 2 4
Would be translated into this (With two indices; one for each material):
[
{
"vertex": [1,0,1,-1,0,1,-1,0,-1,1,0,-1],
"name": "Plane mesh",
"normal": [0,-1,0,0,-1,0,0,-1,0,0,0,0],
"indices0": [0,1,2],
"indices1": [3,0,2]
}
]
Use the online model viewer for the convertion:
http://www.kickjs.org/example/model_viewer/model_viewer.html