User:Karthik0112358

C S Karthik is an undergraduate at IIT-Bombay and is working on addition of an rSQP optimiser for ASCEND during GSOC2011.

Goals

The reduced space SQP (rSQP) algorithm has seen many applications in large-scale engineering models. I intend to accept an input and parse it such that the solver can act on it. Further I am going to take up various test cases and check for bugs/inconsistencies. And if time permits I would like to write an optimization algorithm/code which, based on the given input, decides which is the best solver to send the input to.

Progress reports

Prior to 23 May 2011:

Related to rSQP:

• Started reading Mathematical and High-Level Overview of MOOCHO. However was later redirected to chapter 12 (Nonlinear programming) of "Operations Research: Applications and Algorithms" from Winston, 1994, 3rd (or a later) Ed., Duxbury Press (Belmont, California) as a preliminary reading for mathematical background.
• Completed reading chapter 12 (Nonlinear programming) of "Operations Research: Applications and Algorithms".
• Re-reading Mathematical and High-Level Overview of MOOCHO.
• Revisited theory behind the Simplex Algorithm from "Introduction to Algorithms", 3rd Edition, Page 864-879 authored by Cormen, Leisersin, Rivest, Stein.

Related to Radau5:

• Investigated code ascend/integrator/integrator.h and ascend/integrator/integrator.c to understand the data structures used.
• Devised and tried implementation of various for the mass matrix problem in solvers/radau5/asc_radau5.c.
• Settled on the idea of replacing neq with total number of equations as compared to the previous implementation of number of states.

May 23 - May 29

• Continue reading Mathematical and High-Level Overview of MOOCHO.

May 30 - June 5

• Completed reading Mathematical and High-Level Overview of MOOCHO.

June 6 - June 12 Finding a temporary fix for the mass matrix problem. I have split the task as to finding solution to 2 problems:

• (i) Making sure algebraic equations are being sent to solver.
• (ii) Writing a feasible mass matrix function to generate the mass matrix. This depends on (i).

Regarding Solving Part (i), I made an outside link and was able to capture all the variables involved. Trying to use them to find total number of equations. In completing part (ii) I am facing "INSUFFICIENT MEMORY" problem. Trying to fix that too. I am at present able to count total number of variables, solver variables, independent variables and number of differential equations. I would like to figure out a way to count number of free variables.

I have been able to find a solution to part(i), but it has 2 constraints,

• If number of total variables>>total number of equations, then the max number of substeps has to be reduced.
• The solution involves providing data outside given data structures and thus cannot employed as it is to ascend.

As far as part (ii) goes, there seems to be a simple fix. I am trying to figure it out through Valgrind's Memory loss method.

June 13 - June 19

• Use of valgrind did not provide much insight. Karthik: add DETAILS of what you found here please -- Jpye 07:53, 16 June 2011 (UTC)

June 15

• Trying to understand about expression-evaluation data structures by reading the following c code: ascend/system/relman.c.
• Re-reading Developer's Manual for better clarity.
• Checked out contents of Moocho and broadly read basic documentation.
• Installing MOOCHO

June 16

• Reading relman_diff2() and trying to understand what are the input variables, which header to include, etc.