Sunday, March 12, 2017

removing adware from Intex Aqua 4G Strong mobile phone

The Intex Aqua 4G Strong mobile phone running Android 5.1 which I had purchased to try out Reliance Jio had annoying adware and bloatware in the firmware. I uninstalled as many as I could, but some of them could not be uninstalled. I tried preventing notifications from them by long press on the notification to pull up the app's notification settings, and unchecking notifications from those apps. But still, on every restart, some app would try to install UCNews etc from outside Google Play store, and would be blocked by the security setting to Not Allow Apps from outside the Play store.

Finally thought I should get rid of this malware / adware.

  1. Installed and ran Malwarebytes Anti-Malware app.
  2. It identified the Malware as two apps, with the path to the apks being in the /system/ folder.
  3. Since the apps were masquerading as System apps, they could not be uninstalled except as Root. So, installed Kingroot via the XDA developers forum to root the device. 
  4. Ran Root Checker Basic to check for root - done. 
  5. Installed Root Browser.
  6. When running Root Browser, it asks if it can install some utilities. Said yes, it installed busybox tools. These are necessary to remount the volume as rw, and remove from system folder.
  7. Navigated to /system/apps and removed the folders containing malware.
  8. Ran Malwarebytes again to check that those were removed.
  9. Removed Kingroot through its uninstall option.
  10. Checked that root is now disabled.
  11. Removed Root Checker.
  12. Checked again with Malwarebytes that all is well. Done. 

Monday, February 13, 2017

configuring a DLink DCS-942L camera

In May, I had struggled with port-forwarding, virtual server on router etc while setting up a DLink DCS-942L home network camera. Now, re-configuring it to use a JioFi 4G router, just had to remove the static ip using the Windows setup wizard, then WPS to connect to the wifi network, and that was it. No manual port-forwarding was needed. 

Tuesday, February 07, 2017

ode45 on octave

Trying the gnlse numerical solution for SCG from the Dudley book using GNU Octave - the Matlab clone. The Octave "port" needed some modifications.

  1. The report function doesn't work properly, so probably can be omitted. Instead of outputting a percentage for every step, it outputs at the end. Maybe it is a difference in the flags returned by the ode45 function.
  2. Had to add 'InitialStep', 0.001 to the odeset parameters - or else the error becomes too large and ode45 exits.
  3. Instead of Z which was linspace(0, flength, nsaves), gave [0, flength] as the parameter to ode45 - or else the ode45 in Octave ignores RelTol and AbsTol. 
  4. Then, spline to create a linearly spaced array of our desired spacing.
So, instead of 
[Z, AW]=ode45( @rhs, Z, ifft(A), options .... etc
called it as
[Zoctave, AWoctave]=ode45( @rhs, [0, flength], ifft(A), options .... etc
and then
Z     = linspace(0,flength, nsaves);
AW = spline(Zoctave, AWoctave,Z);

Then, running time - 

Octave modified ugnlse = 166 sec on i7
Matlab  = 281 sec on Athlon

Since python code got 9x speedup on the i7, I guess the Octave ode45 + spline is slower than the Matlab ode45. Still, running on the i7 gets the advantage of more RAM. Doesn't give the out of memory error so easily. 

Monday, February 06, 2017

pynlo on Linux Mint running on i7 Macbook Pro 4GB

Got a Macbook for doing some tests, computations etc.
OS X Snow Leopard 10.6.8
Intel Core i7
2.66 GHz
2 cores

Made it dual boot with Linux Mint 18.1 Cinnamon using rEFInd, installed Anaconda 2.7 for pyNLO.

Anaconda installed with no issues. But pip install needed
apt-get install python-pip
apt-get install python-setuptools
apt-get install python-dev

pip install pyfftw
gave permission errors, so did
pip install pyfftw --user
apt-get install libfftw3-dev

python did not work - no module named matplotlib
pip install matplotlib --user

Then needed
apt-get install python-tk

Finally working. But colours were different in the pcolor plot.

Changed colormap of pcolor using
cmap=plt.get_cmap('viridis') inside pcolor function call.

On my Athlon 32 bit Windows XP laptop - - runs for 15:33 = 933 sec and Mem Error
On the i7 - the same script runs for 1:42 = 102 sec, no Mem Error

So, more than 9x faster.

Sunday, February 05, 2017

status page from uptimerobot have created status pages now, which can be made public also. Our status page is at

Had to make the custom url a redirect, could not make it a subdomain, since Cloudflare complained that two separate accounts cannot CNAME each other. 

Tuesday, January 31, 2017

trying vlc-warp build and other warping on Macbook

The vlc-warp code, when directly tried a build on Linux Mint 18.1 running on an i7 Macbook Pro, gave the error that
configure: error: libavcodec versions 56 and later are not supported yet.

When compiling on a Live DVD of Ubuntu 12.04, compiles OK. But that build will not run on the Linux Mint 18.1 with accelerated graphics. And the Live DVD will not boot with accelerated graphics! So, as of now, am pausing these efforts.

Trying the recommended way to compile on Mac OS - that needs the latest version of Xcode, and our Mac is running 10.8 Snow Leopard.

Tried the Quartz Composer patch from Paul Bourke - that also had some version compatibility issues, I guess, did not work on first few attempts.

Then directly tried the compiled warp-player from Paul Bourke - that itself was skipping frames when trying to warp and play a 50 Mbps 2K fulldome movie. So, pausing these efforts to make a realtime warping player work on this machine. 

Monday, January 30, 2017

Airtel SIM language selection loop

An occasional problem with Xiaomi Mi3 phone - Airtel sim language selection menu comes up again and again - seen for example after a change of SIM.

Solution seems to be to shut down the phone and start it again.