Data visualization tools

seaborn -- https://seaborn.pydata.org/
lighting-viz --http://lightning-viz.org/

Numpy, how to divide the row by its sum efficiently

Method #1: use None (or np.newaxis) to add an extra dimension so that broadcasting will behave:

>>> e
array([[ 0.,  1.],
       [ 2.,  4.],
       [ 1.,  5.]])
>>> e/e.sum(axis=1)[:,None]
array([[ 0.        ,  1.        ],
       [ 0.33333333,  0.66666667],
       [ 0.16666667,  0.83333333]])

Method #2: go transpose-happy:

>>> (e.T/e.sum(axis=1)).T
array([[ 0.        ,  1.        ],
       [ 0.33333333,  0.66666667],
       [ 0.16666667,  0.83333333]])

(You can drop the axis= part for conciseness, if you want.)

Method #3: (promoted from Jaime's comment). (only works Numpy 1.7+)

Use the keepdims argument on sum to preserve the dimension:

>>> e/e.sum(axis=1, keepdims=True)
array([[ 0.        ,  1.        ],
       [ 0.33333333,  0.66666667],
       [ 0.16666667,  0.83333333]])

The Gap between two displays under MATE desktop UBUNTU

I found a related question on Ask Ubuntu which sort of did the trick for me. Instructions for the whole process, including creating the "gap" between monitors (works at least on Ubuntu 14.04): Find out the current total screen size (assuming there's currently no virtual gap between monitors): $ xrandr | grep Screen Screen 0: minimum 320 x 200, current2048 x 1280, maximum 32767 x 32767 Add the desired gap size in pixels to the width (first value displayed after current – in my case, 2048). I chose a gap of 136 pixels, so I'd have a new screen width of 2184. Set the new screen size: xrandr --fb 2184x1280 Find out the display name of your right monitor: $ xrandr | grep ^[^\(]*right HDMI3connected 1024x1280+1024+0 right (normal left inverted right x axis y axis) 376mm x 301mm Virtually move the right monitor further to the right to create the gap. Add your gap size to the third number displayed by the above command (highlighted in bold). In my example, this is 1024+136=1160: xrandr --output HDMI3 --pos 1160x0 Now, make Compiz handle the whole area as one single screen Start CompizConfig Settings Manager (installable with sudo apt-get install compizconfig-settings-manager) Go to "General Options" plugin (e.g. type this in search box) Select tab "Display Settings" Uncheck "Detect Outputs" If this doesn't already do the trick, right click on each line listed under "Outputs", select "Edit" and delete their content. When maximizing a window, it will now stretch both monitors. Fullscreen will also stretch both monitors. Clearly, this isn't ideal, as most of the time it is desirable that maximized windows fill a single monitor. This means, the "Detect Outputs" Compiz option will have to be checked and unchecked depending on what behavior is currently desired. A note to user with non-English locale: If you can't find the CompizConfig plugin and setting because you don't know how their names were translated, start CompizConfig like so:

Several Tricks

1. Print .JSON file nicely by using python:
  

python -m json.tool my_json.json

2. Read how many words in a line:

echo "abc,def,ghi"  | tr ',' ' ' | wc  

How can I reconcile detached HEAD with master/origin?

First, let’s clarify what HEAD is and what it means when it is detached. 

HEAD is the symbolic name for the currently checked out commit. When HEAD is not detached (the “normal”¹ situation: you have a branch checked out), HEAD actually points to a branch’s “ref” and the branch points to the commit. HEAD is thus “attached” to a branch. When you make a new commit, the branch that HEAD points to is updated to point to the new commit. HEAD follows automatically since it just points to the branch.

• git symbolic-ref HEAD yields refs/heads/master
  The branch named “master” is checked out.
• git rev-parse refs/heads/master yield 17a02998078923f2d62811326d130de991d1a95a
  That commit is the current tip or “head” of the master branch.
• git rev-parse HEAD also yields 17a02998078923f2d62811326d130de991d1a95a
  This is what it means to be a “symbolic ref”. It points to an object through some other reference.
  (Symbolic refs were originally implemented as symbolic links, but later changed to plain files with extra interpretation so that they could be used on platforms that do not have symlinks.)

We have HEAD → refs/heads/master → 17a02998078923f2d62811326d130de991d1a95a

When HEAD is detached, it points directly to a commit—instead of indirectly pointing to one through a branch. You can think of a detached HEAD as being on an unnamed branch. 

• git symbolic-ref HEAD fails with fatal: ref HEAD is not a symbolic ref
• git rev-parse HEAD yields 17a02998078923f2d62811326d130de991d1a95a
  Since it is not a symbolic ref, it must point directly to the commit itself.

We have HEAD → 17a02998078923f2d62811326d130de991d1a95a

The important thing to remember with a detached HEAD is that if the commit it points to is otherwise unreferenced (no other ref can reach it), then it will become “dangling” when you checkout some other commit. Eventually, such dangling commits will be pruned through the garbage collection process (by default, they are kept for at least 2 weeks and may be kept longer by being referenced by HEAD’s reflog).

¹ It is perfectly fine to do “normal” work with a detached HEAD, you just have to keep track of what you are doing to avoid having to fish dropped history out of the reflog.

---

The intermediate steps of an interactive rebase are done with a detached HEAD (partially to avoid polluting the active branch’s reflog). If you finish the full rebase operation, it will update your original branch with the cumulative result of the rebase operation and reattach HEAD to the original branch. My guess is that you never fully completed the rebase process; this will leave you with a detached HEAD pointing to the commit that was most recently processed by the rebase operation.

To recover from your situation, you should create a branch that points to the commit currently pointed to by your detached HEAD:

git branch temp
git checkout temp

_{(these two commands can be abbreviated as git checkout -b temp)}

This will reattach your HEAD to the new temp branch.

Next, you should compare the current commit (and its history) with the normal branch on which you expected to be working:

git log --graph --decorate --pretty=oneline --abbrev-commit master origin/master temp
git diff master temp
git diff origin/master temp

(You will probably want to experiment with the log options: add -p, leave off --pretty=… to see the whole log message, etc.)

If your new temp branch looks good, you may want to update (e.g.) master to point to it:

git branch -f master temp
git checkout master

_{(these two commands can be abbreviated as git checkout -B master temp)}

You can then delete the temporary branch:

git branch -d temp

Finally, you will probably want to push the reestablished history:

git push origin master

You may need to use --force to push if the remote branch can not be “fast-forwarded” to the new commit (i.e. you dropped, or rewrote some existing commit, or otherwise rewrote some bit of history).

If you were in the middle of a rebase operation you should probably clean it up. You can check whether a rebase was in process by looking for the directory .git/rebase-merge/. You can manually clean up the in-progress rebase by just deleting that directory (e.g. if you no longer remember the purpose and context of the active rebase operation). Usually you would use git rebase --abort, but that does some extra resetting that you probably want to avoid (it moves HEAD back to the original branch and resets it back to the original commit, which will undo some of the work we did above).

ubuntu MAAS

1. configure the IP address of MAAS server: (the second one works)

sudo dpkg-reconfigure maas-cluster-controller
sudo dpkg-reconfigure maas-region-controller    

weird DELL's IPMI (or IDRAC, whatever)

the –o intelplus is an additional command line option / OEM specifier. Please try it together with the other options, e.g.

ipmitool –I lanplus –U user –P password –H host –o inteloem mc info

should give you the same information as with an IPMI 1.5 connection.

ipmitool –I lan –U user –P password –H host –o inteloem mc info

If this works you have RMCP+ working and you can try to activate sol

ipmitool –I lanplus –U user –P password –H host –o inteloem sol activate

I'm able to use ipmitool with a remote machine using the 'lan' protocol, but 'lanplus' fails for every command. I'm trying to get SOL working, but I'm having no luck with lanplus at all:

ipmitool -v -I lanplus -E -H 10.0.40.240 -U admin lan print

Error in open session response message : insufficient resources for session

Error: Unable to establish IPMI v2 / RMCP+ session

I can ping the remote BMC with both ipmiping and rmpcping

The machine is a Dell CS23, the BMC has IPMI v2. I'm using ipmitool v1.8.12 compiled from source.
I've tried cold resetting the BMC, but it doesn't help.