## [GSoC-2019|VisMa|Mayank] GSoC 2019, A final wrap up!

visma-VISualMAth, an equation solver and visualizer, which aims at showing the step-by-step solution & interactive plots of a given equation. As of now, VisMa is able to deal with matrices, multi-variable simultaneous equations & higher degree equations (up to four degrees) as well.

Via this blog, I will be giving a final wrap to everything I did during my wonderful stay at AerospaceResearch.net.

Before the start of GSoC 2019, following major deliverables were decided:

• Re-writing simplify modules (addsub.py & muldiv.py) by using build-in class methods.
• Adding support for Expression simplification
• Adding a module for Discrete Mathematics
• Adding support for equation solvers for cubic & biquadratic polynomials.
• Adding support for simultaneous equations
• Enhancing integration & derivation modules
• Integrating matrix module with GUI
• Rendering LaTex and Matplots in CLI
• Including a Discrete Mathematics Module (including combinatorics, probability & statistics module)

All of the above-mentioned deliverables have been implemented. The commits referencing these changes are available at this link.

Below GIF shows the now integrated CLI module in action:

Some images showing matrix operations with VisMa are as follows:

Adding new modules & improving old ones was a great learning experience. Bugs were sometimes annoying however, each bug resulted in learning something new. That pretty much sums up all I did during GSoC.

I have written a developer blog for each of the Phases of GSoC, they are available as follows:

• Phase I – Improving simplify module, simultaneous equations & higher degree equations
• Phase II – Combinatorics, Statistics, Simple Probability, Expression simplification etc.
• Phase III & a CHANGELOG – More cases on Expression Simplification, Constant raised to some fractional (or solvable) powers, documentations etc.

Ideas to be implemented in future:

• Implementing an Equation Scanner should be an idea in the coming future. It would improve the user interface & productivity of application many folds.
• Adding feature for simplification of trigonometric variables could be an important addition.
• Making an Android App & Web App for the project could be a great idea too. Anything available as an app or a web app has indeed a greater audience.

Some links which readers might find useful:

## [GSoC-2019|VisMa|Mayank] Phase III & Final project report

In this blog post, I will be summarising all the work done during phase III (i.e. last phase of GSoC 2019).

This phase the major target was to wrap up all the work done during Phase I and Phase II. The first target was to implement GUI & CLI in matrices. The integration of GUI & CLI in matrices was pending from a long time and this was the time to get it done. The integration, however, was a bit tricky as it was very obvious that the usual parsers and tokenizers could not be used to integrate Matrices with GUI/CLI. We had to make an entirely new module which would be able to parse matrices (i.e. accept them as some input from the user and perform operations accordingly on them). We finally were able to properly integrate this module in GUI/CLI. It was worth the time & patience as the results were good. For now, the user has to enter the matrices in some specific Python list type pattern. In later versions, we can add options for adding matrices interactively by GUI.

Some screenshots of Matrix Module in action are:

The next part was adding test cases for Statistics modules (which were implemented during Phase II). Also, we added Equation Plotting feature in CLI during this part. It involved creating another Qt window equivalent to the plotter used in GUI version.

The last target of this phase was to add code to deal with cases when the Constant was raised to some fractional or Expression power. Earlier VisMa was able to handle only those cases when power was some Integer. The solution to this problem was to consider all the exponents as some object of Expression Class. Now since Expression simplification was done earlier this could be achieved. Also, I added the cases when Expression classes are involved in the Equation inputted by the user. Finally, our last target was to add the necessary documentation so that new users can get comfortable with the codebase. Personally, when I started to contribute to the project I found a lot of help because of docstrings & comments. Earlier developers (My mentors) have maintained a very well documented codebase, so it was my responsibility to carry this tradition forward.

To sum up, all the work done I am updating a list of all that we achieved during GSoC. The Changelog is as follows:

1. Simplify module written in Object-Oriented Programming Design.

2. `__add__``__sub__ `,`__mul__` & `__truediv__` methods for most of the classes (like ConstantExpressionTrigonometric etc) have been added.

3. Discrete Mathematics Module has been added:
a. Combinatorics modules like Combinations, Permutations & Factorial modules (with GUI/CLI implementations)
b. Statistics Module containing mean, median and mode
c. Simple probability modules
d. Bit-wise Boolean Algebra module

4. Simultaneous Equation solver has been implemented

5. The plotter is now able to plot in both 2D and 3D for equations having one, two or three variables. It has been implemented in the CLI version

6. Equation solvers for higher degrees (Third & fourth degree) using determinant based approach have been added.

7. Integrations and differentiation modules are now implemented in all Function Classes (Trigonometry, Exponential and Logarithmic)

8. Integration & Differentiation modules have been rewritten to follow Object-Oriented Style.

9. Product Rule for Differentiation & Integration by parts module has been added.

10. Tokenize module is now improved to consider power operator (earlier it ignored power operator in many cases)

11. With above improvement Expressions raised to some power are duly handled by VisMa.

12. Parsing modules for printing matrices in Latex and string form have been added. With this matrix operations are now well implemented in GUI & CLI.

13. Expression simplification is now completely supported by VisMa. Almost all cases of Expression classes being involved in input equation have been taken care of. Multiple brackets are now also taken care by VisMa (for this the modules using recursion have been implemented).

14. The cases where Constant are raised to some fractional power or some solvable term have been covered.

The points where we will be working now are:

1. We can implement an Equation Scanner in the project. This way a user will be able to scan an image of the equation and it will be solved by VisMa. This was an idea during this GSoC but due to time constraints, we were not able to work in it for now.

2. VisMa is not friendly with Trigonometric expressions, there is a need to deploy some code in simplification module for taking care of this thing.

Overall, working in this community as a GSoC student was a great experience. It was hard but fun to stay within deadlines, fixing bugs, deploying new ideas etc. Feel free to connect with me on Twitter (https://twitter.com/mayank1Dhiman) & GitHub (https://github.com/mayankDhiman).

## [GSOC2019|VisMa|Mayank] Week 5 to 7 (Phase II)

It’s been almost two months I started to work on VisMa as my GSoC-19 Project (although I have been working with the community since December 2018) and it has been a quiet learning experience. This post will focus on technical details of what VisMa team has improved in the project roughly during the span of Phase II of GSoC.

Week 6: This week our task was to improve the integration and differentiation module of the project. The earlier logic and code for these two modules was beautifully implemented. My task was to add integration and derivation function to all Function Classes of the Project. Function Classes, in very simple terms, is a name given to a super-class of tokens whose subclasses are Constant, Variable etc. I had to add differentiation and integration for all these subclasses. Many of these were implemented but some were missing. Among missing ones, were Trigonometric, Exponential and Logarithmic Classes. I wrote the respective functions for all these Function Classes, also adding comments and animations side by side. Also, I refactored the existing code in differentiation & integration modules to follow an object-oriented style. Also added some test cases for same.

Week 7: The task of this week was focussed on improving the tokenizing module, adding some corner cases in Expression Simplification (involving exponents) and fixing some potential bugs. The tokenizer module treated Variable raised to some power, as a single token of Variable type (with the value of pow parameter set to power), but it didn’t recognise power operator in any case, my task was to fix it for recognising power operator. The potential bugs with Expression Simplification could only be resolved after it was done. The Expression Simplification follows a recursive logic, thus adding even a small improvement in that module sometimes become much confusing. But finally it was done in a nice manner, and VisMa is now able to deal with almost all the cases involving Expressions and Exponents. I also added test cases to reflect the new behaviour of the project.

Current Goal: As of now, I am working on implementing Matrix Module in CLI/GUI, the matrix operations have been implemented and now the next goal is to enable users to enter Matrices interactively in CLI/GUI

Below images illustrate the GUI/CLI representation of „factorial“, „combination“ and „permutation“ features in action.

Lastly, the project development is going at a good rate :). Some times it becomes buggy and confusing too, but lastly, it is a learning process and each bug does teach something new. I will soon be updating all the logic and working of the project in the wiki so that future developers can be helped.

Chears to space, Open Source, Maths & Code!

## [GSOC2019|VisMa|Mayank] Week 1 to 3

This blog post is intended to pen down my experience of working with aerospaceresearch.net and on VisMa – Visual Math as a part of Google Summer of Code 2019. A part of this blog post will be about how it feels to be working here & other parts will focus on technicalities of the project (about how VisMa has been improved over the past three weeks).

Firstly, working with aerospaceresearch.net has been a great experience. The mentors of the project Shantanu, Manfred & Siddharth are very helpful. We almost regularly have chat on Zulip (& sometimes on WhatsApp) wherein we discuss the plans for the project and about implementation. Owing to these healthy discussions the project development is going at a fast rate (which is indeed a good thing!). The code base of VisMa is very well written and the complex task of simplifying mathematical equations has been beautifully coded. About the workload, I work regularly for 5 – 6 hours, but sometimes when a crucial bug finds its way in, the work time has to be increased. Overall it’s a Fun & Learn experience.

Now let’s talk about what we (the VisMa Team) have achieved so far. During the community bonding period, I spend my time to get equipped with basics of PyQt (on which the GUI of VisMa is based) and spend the remaining time studying the tokenizing and simplify modules. Honestly, these modules were hard to understand. But the effort turned fruitful during the coding period. Also, I completed the task of simultaneous equation solver during this time. The logic was easy to frame, but the inclusion of comments and animations was tricky and involved the entire redesigning of the LaTex generator module (the part which created the final latex to be displayed in GUI).

Over to the first week of the coding period, the task which was decided was to re-design all the simplify module in an object-oriented fashion, which before coding period I believed would be most difficult to write (after all more than 2000 lines of complex Pythonic logic, to be honest, was scary). But, efforts to understand module during the Community Bonding Period turned out to be fruitful, and I was happy to achieve this task in the desired time. Like any other programming project, there are some minor bugs out there, which will be fixed in the upcoming time!

Coming to week second, we decided to work on Expression Simplification. Now, what expression is, briefly (& vaguely) any part of inputted equation enclosed in brackets can be termed as an Expression. So like when we solve an equation by hand, we solve the bracket part first, our task was to make visma do same! Earlier it didn’t support Expression simplification. For that, we decided to go for a complex recursive logic (solving the inner expression first then the outer expressions & so on). Recursive logic was complex & time consuming to implement, taking care of all comments & animations during recursion was a challenge. It took somewhat 9 days to come up with something fruitful. But yes it was worth it, VisMa could easily solve Expressions now. A happy moment indeed! 🙂

Next phase was to include a new module to VisMa. It was decided it has to be a Discrete Math module (‚cause why the heck not!). We decided to go for Combinatorics stuff first, thus implementing Combinations & Permutation stuff. These modules require factorial of a number, I got this idea why not to implement factorial as a separate module and then use in Permutations & Combinations stuff. This added another factorial feature to VisMa.

For now, I am working of adding triple degree equation solvers to project. We as of now have decided to do so using Cardano Algorithm. If this turns out well it will also be done for four-degree equations. After this will be done, VisMa will be capable of solving & showing detailed steps for up to 4-degree equations.

Below is a short GIF showing some of new features in action:

Hope you enjoyed reading Chapter One of my Developer Diary. From now on, I will write these blogs bi-weekly.

Chears to Code, Space & Maths!