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Cosine Similarity between 2 Number Lists
...e the nuts-and-bolts implementation:
import math
def cosine_similarity(v1,v2):
"compute cosine similarity of v1 to v2: (v1 dot v2)/{||v1||*||v2||)"
sumxx, sumxy, sumyy = 0, 0, 0
for i in range(len(v1)):
x = v1[i]; y = v2[i]
sumxx += x*x
sumyy += y*y
sumxy...
ReSharper Abbreviations List: Where can I modify it?
...
Just an update that in VS 2010 with ReSharper 6.1 the list of abbreviations now appears under ReSharper/Options/Code Editing/C#/C# Naming Style/Advanced Settings - at the bottom of the panel is a text area with a space-separated list of uppercase abbreviations. This took...
API Versioning for Rails Routes
...espace :api do
namespace :v1 do
resources :users
end
namespace :v2 do
resources :users
end
match 'v:api/*path', :to => redirect("/api/v2/%{path}")
match '*path', :to => redirect("/api/v2/%{path}")
end
If your mind is still intact after this point, let me explain.
First,...
Finding quaternion representing the rotation from one vector to another
...
Quaternion q;
vector a = crossproduct(v1, v2);
q.xyz = a;
q.w = sqrt((v1.Length ^ 2) * (v2.Length ^ 2)) + dotproduct(v1, v2);
Don't forget to normalize q.
Richard is right about there not being a unique rotation, but the above should give the "shortest arc," which...
For each row return the column name of the largest value
...make examples using sample reproducible):
DF <- data.frame(V1=c(2,8,1),V2=c(7,3,5),V3=c(9,6,4))
colnames(DF)[apply(DF,1,which.max)]
[1] "V3" "V1" "V2"
A faster solution than using apply might be max.col:
colnames(DF)[max.col(DF,ties.method="first")]
#[1] "V3" "V1" "V2"
...where ties.method...
How can I list all tags in my Git repository by the date they were created?
...ioned by DarVar below)
As an example, in the git/git repo it will list the v2.10.0 tag last:
v2.9.1
v2.9.2
v2.9.3
v2.10.0-rc0
v2.10.0-rc1
v2.10.0-rc2
v2.10.0
The default order would not (git tag):
v2.1.2
v2.1.3
v2.1.4
v2.10.0
v2.10.0-rc0
v2.10.0-rc1
v2.10.0-rc2
v2.2.0
...
How to format a floating number to fixed width in Python
...
In Python 3.
GPA = 2.5
print(" %6.1f " % GPA)
6.1f means after the dots 1 digits show if you print 2 digits after the dots you should only %6.2f such that %6.3f 3 digits print after the point.
...
How to combine multiple conditions to subset a data-frame using “OR”?
...
my.data.frame <- subset(data , V1 > 2 | V2 < 4)
An alternative solution that mimics the behavior of this function and would be more appropriate for inclusion within a function body:
new.data <- data[ which( data$V1 > 2 | data$V2 < 4) , ]
Some peopl...
使用App Inventor扩展实现多点触控：Rotation Detector · App Inventor 2 中文网
...
float v1x = fX-sX;
float v1y = -(fY-sY);
float v2x = nfX-nsX;
float v2y = -(nfY-nsY);
float angle1 = normalizeAngle((float) Math.atan2(v1y, v1x),v1x,v1y);
float angle2 = normalizeAngle((float) Math.atan2(v2y, v2x),v2x,v2y);
Log.i("Rotat...
使用App Inventor扩展实现多点触控：Rotation Detector · App Inventor 2 中文网
...
float v1x = fX-sX;
float v1y = -(fY-sY);
float v2x = nfX-nsX;
float v2y = -(nfY-nsY);
float angle1 = normalizeAngle((float) Math.atan2(v1y, v1x),v1x,v1y);
float angle2 = normalizeAngle((float) Math.atan2(v2y, v2x),v2x,v2y);
Log.i("Rotat...