Command Repository (Running Post)
Table of Contents
- C++
- Docker
- Git
- Julia
- Markdown Snippets
- MATLAB
- Python
- PyTorch
- Recover Unsaved Sublime Text
- ROS 1
- ROS 2
- Terminal tools
- Benchbot
- Acknowledgements
C++
Sort vector nums while keeping track of indices
vector<pair<int,int>> vp(nums.size());
for(int i=0; i<nums.size(); i++){
vp[i] = make_pair(nums[i],i);
}
sort(vp.begin(), vp.end());
Docker
Run an interactive bash
docker run -it --gpus all nvidia/cuda:11.1-base bash
Start docker container (epic_faraday)
docker start epic_faraday
Execute bash in docker container (epic_faraday)
docker exec -it epic_faraday bash
Stop docker container
docker stop epic_faraday
View active containers
docker ps -a
For GUI
Check xeyes Dockerfile and reference
For matplotlib, check Dockerfile in cs747 repo
Git
For cloning single branch
git clone --single-branch --branch 2020_Autumn git@github.com:trunc8/Sem_Coursework.git
For cloning another branch after that
git remote set-branches --add origin 2019_Autumn
git fetch origin 2019_Autumn:2019_Autumn
Realizing that there is a submodule
git rm -r --cached projectfolder
git submodule add url_to_repo projectfolder
After committing in submodule, in superset repo
git submodule update --remote --merge
git add .
gcmsg "Message"
git push
Delete local branch
git branch -d <local-branch>
git branch -D <local-branch> (forceful)
Delete remote branch
git push origin --delete <remote-branch-name>
Discard local changes
# Discard all local changes, but save them for possible re-use later
git stash
# Discarding local changes (permanently) to a file
git checkout -- <file>
# Discard all local changes to all files permanently
git reset --hard
Julia
... used in function calls for spreading the arguments
Hello world in Julia
println("Hello world")
Plotting tangent to sine curve
import Pkg; Pkg.add("Plots"); Pkg.add("ForwardDiff")
using Plots
import ForwardDiff as FD
function first_order_taylor(f::Function, x_bar::Float64, x::Float64)::Float64
return f(x_bar) + FD.derivative(f, x_bar) * (x - x_bar)
end
let
x = -2*pi:0.01:2*pi
y = sin.(x)
x_bar = randn()
tangent_at_xbar = [first_order_taylor(sin, x_bar, x[i]) for i=1:length(x)]
scatter([x_bar], [sin(x_bar)])
plot!(x, y)
plot!(x, tangent_at_xbar)
end
Concatenate matrices in block diagonal form
cat(I(3),-I(3); dims=(1,2))
Markdown Snippets
Collapsible Section
<details>
<summary>Update!</summary>
Our repository is now public <a href="https://github.com/trunc8/international-micromouse-techfest2020">here</a>. All elements for the simulation are self-contained.
</details>
Footnote
### Author(s)
* **Siddharth Saha** - [trunc8](https://github.com/trunc8)
<p align='center'>Created with :heart: by <a href="https://www.linkedin.com/in/sahasiddharth611/">Siddharth</a></p>
Emojis
Github markdown allows :heart: to be rendered, but converting it to html doesn't render it on a webpage.
For that purpose, use fa fa-icons (css)-
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
How to use?
<i class="fa fa-heart" aria-hidden="true"/>
Basic Tags
#### Headings
# H1
## H2
### H3
#### H4
##### H5
#### Bold
**bold text**
#### Italic
*italicized text*
#### Blockquote
> blockquote
#### Ordered List
1. First item
2. Second item
3. Third item
#### Unordered List
- First item
- Second item
- Third item
#### Code
`code`
#### Link
[title](https://www.example.com)
#### Horizontal Rule
---
Image
# Example:
<p align="center">
{:width="200px" height="200px"}
</p>
# Only works in Markdown Preview Renderer
<p align="center">
{:width="200px" height="200px"}
</p>
# Left aligned (Height doesn't work with Kramdown; Fails for GitHub)
{:width="200px"}
# Centering for GitHub and Kramdown:
<p align="center">
<img src="https://trunc8.github.io/assets/img/profile-pic.jpg" width="200">
</p>
Video
<iframe width="560" height="315"
src="https://www.youtube.com/embed/VIDEO_ID?rel=0&controls=1&start=0"
frameborder="0"
allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture"
allowfullscreen></iframe>
<br />
Extended Syntax
Not all Markdown applications support these elements.
#### Table (Doesn't work with Kramdown)
| Syntax | Description |
| ----------- | ----------- |
| Header | Title |
| Paragraph | Text |
#### Fenced Code Block
```
{
"firstName": "John",
"lastName": "Smith",
"age": 25
}
```
#### Footnote
Here's a sentence with a footnote. [^1]
[^1]: This is the footnote.
#### Custom Heading ID
### My Great Heading {#custom-id}
#### Definition List (Doesn't work with Kramdown)
term
: definition
#### Strikethrough
~~The world is flat.~~
#### Task List
- [x] Write the press release
- [ ] Update the website
- [ ] Contact the media
### Rendering this md from Sublime (If Markdown Preview is installed)
Press `Alt+M`
Latex in HTML (works with Kramdown)
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
tex2jax: {
inlineMath: [['$','$'], ['\\(','\\)']],
processEscapes: true},
jax: ["input/TeX","input/MathML","input/AsciiMath","output/CommonHTML"],
extensions: ["tex2jax.js","mml2jax.js","asciimath2jax.js","MathMenu.js","MathZoom.js","AssistiveMML.js", "[Contrib]/a11y/accessibility-menu.js"],
TeX: {
extensions: ["AMSmath.js","AMSsymbols.js","noErrors.js","noUndefined.js"],
equationNumbers: {
autoNumber: "AMS"
}
}
});
</script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS_CHTML"></script>
Latex in Markdown Preview
# VARIANT 1
<!DOCTYPE html><script src="https://cdn.jsdelivr.net/npm/texme@0.7.0"></script><textarea>
## Euler's Identity
In mathematics, **Euler's identity** is the equality
$$ e^{i \pi} + 1 = 0. $$
## Explanation
Euler's identity is a special case of Euler's formula from complex
analysis, which states that for any real number $ x $,
$$ e^{ix} = \cos x + i \sin x. $$
Further reference: https://github.com/codeassign/markjax
# VARIANT 2.1 (Markdown Preview)
<script>
MathJax = {
tex: {
inlineMath: [['$', '$'], ['\\(', '\\)']]
}
};
</script>
<script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js"></script>
# VARIANT 2.2 (Markdown Preview)
> mathjax-config.js (filename)
window.MathJax = {
tex: {
inlineMath: [['$', '$'], ['\\(', '\\)']]
},
svg: {
fontCache: 'global'
}
};
<script src="mathjax-config.js" defer></script>
<script type="text/javascript" id="MathJax-script" defer src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js"></script>
# How to use VARIANT 2?
Inline: `\\(a^2\\)`
Outline: `\\[ a^2 = b^2 + c^2 \\]`
Inline: `$|\vec{A}|=\sqrt{A_x^2 + A_y^2 + A_z^2}.$`
Outline: `$$|\vec{A}|=\sqrt{A_x^2 + A_y^2 + A_z^2}.$$`
MATLAB
Starter comment
%==========================================
% Title: TITLE
% Author: trunc8
% Date: DATE
%==========================================
Create a legend for a variable used as for loop iteration
% Declare your legend_values in a column vector Pr
legend(strcat('p=',num2str(Pr')),'Interpreter','latex');
MATLAB matrix to LaTeX
% Credits: Lu Ce
%% Clear command window
clc;
%% Choose matrix to convert
M = rand(4, 5);
%% Convert
% Get matrix dimensions
m = size(M, 1);
n = size(M, 2);
% Create first line
s = sprintf(' \\begin{bmatrix}\n ');
% Add matrix content
for k = 1:m
for l = 1:n
s = sprintf('%s %6.3f', s, M(k, l)); % print 3 decimal places, align to 6 characters
if l < n
s = sprintf('%s &', s);
end
end
if k < m
s = sprintf('%s \\cr', s);
end
s = sprintf('%s\n ', s);
end
% Add last line
s = sprintf('%s\\end{bmatrix}\n', s);
% Print the result
disp(s);
Python
Nested for loops in one line
import itertools
for i, j in itertools.product(range(x), range(y)):
Loop simultaneously
for i, j in zip(range(x), range(y)):
Difference between zip and itertools.product:
import itertools
x=3; y=2
print(list(itertools.product(range(x), range(y))))
# Output: [(0, 0), (0, 1), (1, 0), (1, 1), (2, 0), (2, 1)]
print(list(zip(range(x), range(y))))
# Output: [(0, 0), (1, 1)]
Identical elements in two lists
list(set(t1).intersection(set(t2)))
Append to script’s path location
cwd = os.path.dirname(os.path.abspath(__file__))
os.path.join(cwd,FILEPATH)
Idiom to reverse a sequence
a = np.arange(10)
print(a[::-1])
Matplotlib: Plot cv2 image in matplotlib
im1 = cv2.imread('kind_doggo.png')
plt.imshow(im1[:,:,::-1])
# Effectively flipping last dimension order: BGR (cv2) -> RGB (plt)
plt.show()
Numpy: Divide each row by a vector element
data = np.array([[1,1,1],
[2,2,2],
[3,3,3]])
vector = np.array([1,2,3])
# Inherently each element divides across entire column, so take transpose
sub_result = (data.T - vector).T
# array([[0, 0, 0],
# [0, 0, 0],
# [0, 0, 0]])
div_result = (data.T / vector).T
# array([[1., 1., 1.],
# [1., 1., 1.],
# [1., 1., 1.]])
Numpy: Stack and axis
# arr.shape = (4,3)
np.stack((arr, arr), axis=0) # shape: (2,4,3)
np.stack((arr, arr), axis=1) # shape: (4,2,3)
np.stack((arr, arr), axis=2) # shape: (4,3,2)
np.stack((arr, arr), axis=-1) # shape: (4,3,2)
Numpy: Precision of 3 decimal places and suppress scientific notation
np.set_printoptions(precision=3, supress=True)
Numpy: Sum axis
data = np.array([[1,1],
[2,2],
[3,3]])
np.sum(data, axis=0) # array([6, 6])
np.sum(data, axis=1) # array([2, 4, 6])
'''
Explanation: Shape is (3,2)
- Axis 0 will sum along shape "3"
- Axis 1 will sum along shape "2"
'''
PyTorch
Load a model’s weights
# Import model's class somehow or define it here
model = Model_Class().to("cuda")
model.load_state_dict(torch.load(model_filename))
model.eval()
model(inputs)
Recover Unsaved Sublime Text
cd ~/.config/sublime-text-3/Local
vim Session.sublime_session
## Press the '/' key
## Search for whatever string you remember from the lost file
## Press 'Enter' and iterate through results using 'n' key
## After finding the lost text, convert all the '\n' into newlines
ROS 1
Barebones package
catkin create pkg hello_package
cd hello_package
mkdir src && cd src
touch hello_package_node.cpp
package.xml
<?xml version="1.0"?>
<package format="2">
<name>hello_package</name>
<version>0.0.0</version>
<description>The hello_package package</description>
<maintainer email="trunc8@todo.todo">trunc8</maintainer>
<license>TODO</license>
<buildtool_depend>catkin</buildtool_depend>
<depend>roscpp</depend>
</package>
CMakeLists.txt
cmake_minimum_required(VERSION 3.0.2)
project(hello_package)
find_package(catkin REQUIRED
roscpp
)
catkin_package(
)
## Specify additional locations of header files
include_directories(
${catkin_INCLUDE_DIRS}
)
## Declare a C++ executable
## With catkin_make all packages are built within a single CMake context
## The recommended prefix ensures that target names across packages don't collide
add_executable(${PROJECT_NAME}_node src/hello_package_node.cpp)
## Specify libraries to link a library or executable target against
target_link_libraries(${PROJECT_NAME}_node
${catkin_LIBRARIES}
)
hello_package_node.cpp
#include "ros/ros.h"
#include <iostream>
int main()
{
std::cout << "Hello rtr_world" << std::endl;
ROS_INFO("Hello");
return 0;
}
ROS 2
cd into package (e.g., turtlesim)
colcon_cd turtlesim
Return a list of package’s executables:
ros2 pkg executables turtlesim
Start package
ros2 run turtlesim turtlesim_node
Passing ros arguments
ros2 run turtlesim turtlesim_node --ros-args --remap __node:=my_turtle
Nodes
ros2 node list
ros2 node info /my_turtle
Give 2D Pose Estimate from Terminal
ros2 topic pub -r 1 /initialpose geometry_msgs/msg/PoseWithCovarianceStamped "{header: {frame_id: 'map'}}"
Terminal tools
Copy from vim to clipboard
# Linux Xorg
:'<,'>w !xclip -selection clipboard
Color print from vim
# Inside vim
:hardcopy > mydocument.ps
# Exit vim
ps2pdf mydocument.ps
Replace in all files recursively under current directory
# GREP: Replace "/home/trunc8d/catkin_ws/src/chaos" with "$(find chaos)"
grep -rl "/home/trunc8d/catkin_ws/src/chaos" . | xargs sed -i 's/\/home\/trunc8d\/catkin_ws\/src\/chaos/\$\(find chaos\)/g'
# RG: Replace 'category: scribbles' with 'category: ""'
rg --files-with-matches 'category: scribbles' | xargs sed -i 's/category: scribbles/category: ""/g'
Disable caps lock key
xmodmap -e "clear lock"
Toggle caps lock key
xdotool key Caps_Lock
Join Zoom meeting
/bin/xdg-open zoommtg://zoom.us/join?action=join&confno=MEETING_ID&pwd=PWD
Edit pdf
xournal PDF_NAME
Speed-up Video by 2x
mencoder -speed 2 -o OUTPUT.mp4 -ovc lavc - INPUT.webm -oac mp3lame -srate 8000
ffmpeg -i INPUT.webm -filter_complex "[0:v]setpts=2*PTS[v];[0:a]atempo=2[a]" -map "[v]" -map "[a]" -c:v libx264 -c:a aac OUTPUT.mp4
# If input has no audio
ffmpeg -i champ_crude_line_follower.webm -filter_complex "[0:v]setpts=0.5*PTS[v]" -map "[v]" -c:v libx264 -c:a aac champ_crude_line_follower2x.mp4
Convert Google Slides slideshow into video
## Download Google Slides slideshow as PDF_FILE.pdf
## cd into the download location
mkdir Images
pdftoppm -png PDF_FILE.pdf Images/IMAGE_PREFIX
ffmpeg -framerate 1 -i Images/IMAGE_PREFIX-%02d.png -c:v libx264 -profile:v high -crf 20 -pix_fmt yuv420p -r 10 IMAGE_PREFIX.mp4
# Above "%02d" stands for two-digit sequential numbering like 01,02,...10,11,...
# The first framerate (-framerate 1) denotes delay for each slide
# The second framerate (-r 10) denotes number of times each slide image
# is duplicated. Adds smoothness, I believe.
# See acknowledgement references below for more information
Benchbot
cd $HOME
benchbot_run --robot carter --env miniroom:1 --task semantic_slam:passive:ground_truth -f
benchbot_run --robot carter --env house:1 --task semantic_slam:passive:ground_truth -f
benchbot_submit --evaluate-results omq --native python3 my_semantic_slam/my_semantic_slam.py
benchbot_submit --evaluate-results omq --results results/YV2.json --native python3 yolo-votenet/main.py > results/YV_frames2.sh
benchbot_submit --evaluate-results omq --results results/votenet.json --native python3 my_semantic_slam/my_semantic_slam.py | tee results/votenet_results2.sh
benchbot_submit --evaluate-results omq --results results/groupfree.json --native python3 shetti-group/my_groupfree_slam.py | tee results/groupfree_results2.sh
benchbot_batch --task semantic_slam:passive:ground_truth --robot carter --envs miniroom:1,miniroom:5 --native python3 my_semantic_slam/my_semantic_slam.py