Cleve Moler has died

212 points by mychele 13 hours ago | 22 comments

nmdeadhead 29 minutes ago |

Cleve was chairman of the C.S. department at the University of New Mexico from 1980 to 1984. I got my MSCS there in 1985, in a large part thanks to Cleve. I never took any of his courses, but I did speak to him off and on, because he was friendly, approachable and was an advocate of me being allowed into their Masters program.

On a couple of occasions Cleve mentioned that he had fairly significant troubles sleeping and I was impressed by how well he performed with so little good sleep. Turns out, I had undiagnosed sleep apnea myself that only got worse over the years (until I had three surgeries to significantly reduce it). During my bad apnea days there were times where I pulled myself together and rallied by remembering Cleve. I'll never be able to repay Cleve for what he did indirectly for me, much less what was direct and deliberate, but I do try to help others and will remain inspired by him until my brain no longer processes.

generuso 7 hours ago |

Cleve Moler was one of the big names in numerical methods, and participated in creation of canonical FORTRAN libraries for solving linear equations, and matrix algorithms more generally.

To teach this more conveniently to his students, he wrote the original version of MATrixLABoratory to allow interactive exploration of the library functions without having to compile FORTRAN code. The original version was about 2000 lines of code in FORTRAN.

Engineering students loved it so much that he decided to make a company around this product. His buddy expanded and rewrote the interpreter in C, for a PC, and the rest is history:

"In 1983 Jack Little suggested the creation of a commercial product based on MATLAB. I said I thought that was a good idea, but I didn't join him initially. The IBM PC had been introduced only two years earlier and was barely powerful enough to run something like MATLAB, but Little anticipated its evolution. He left his job, bought a Compaq PC clone at Sears, moved into the hills behind Stanford, and, with my encouragement, spent a year and a half creating a new and extended version of MATLAB written in C. A friend, Steve Bangert, joined the project and worked on the new MATLAB in his spare time."

User guide for the original version of MATLAB: https://blogs.mathworks.com/cleve/2018/02/05/the-historic-ma...

The source code of the very early (1982?) FORTRAN version of MATLAB: https://github.com/johnsonjh/matlab

The origins of the first PC version: https://blogs.mathworks.com/cleve/2018/03/09/matlab-history-...

MatteoFrigo 6 hours ago | |

A true giant. His algorithm for Pythagorean addition, which computes sqrt(a^2 + b^2) without taking square roots, is a wonderful gem.

Fun anecdote about early Matlab. In the '80s, while in high school, I "acquired" the source code of an early version of matlab, similar to the one that you linked. An email from Cleve Moler in 1990 asked people not to distribute the code, so I didn't give it to anybody. In the late '90s I visited Cleve Moler at his Mathworks office, and he proudly showed the early Matlab running on DOS, remarking that he only had that binary but had lost the source code. So I gave it to him.

bachmeier 1 hour ago | |

MATLAB competed in the same space with a piece of software called GAUSS. Both had their initial commercial release in 1984. MATLAB eventually went on to dominate most areas, but I had to deal with the pain of writing my dissertation in GAUSS, which continues to be heavily used in specific areas today.

https://en.wikipedia.org/wiki/GAUSS_(software)

ozgung 5 hours ago | |

I haven't realized MATLAB was that old. It's one of the earliest software for PC yet still almost without alternative for engineers in 2026.

jeremyjh 5 hours ago | |

I didn’t know his name but certainly knew about MATLAB. He sounds worthy of a black bar to me.

simoneau 36 minutes ago |

I was lucky to have the office across the hall from him at MathWorks around 2000. He was always interested in chatting with whomever came by and learning about what they were working on. He was always a college professor at heart.

simoneau 23 minutes ago | |

He called me into his office one day to play me a voicemail. It was Steve Jobs asking him what he could do to get MATLAB shipping on the Mac again.

MathWorks had dropped the platform because of it's then-low market share. Steve was having trouble selling Macs to universities because MATLAB was so important there. Apple ended up sending MathWorks a bunch of Macs for the build-end-test system, and MATLAB did soon return to the Mac.

simoneau 29 minutes ago | |

Penny Anderson was in his office one day. They were trying to figure out which LAPACK numerical algorithm to use under the covers to power some MATLAB function. The different algorithms performed better for different types of matrices and different hardware specifications. They were trying to work out some heuristic where they could automatically pick the right one for the user, but they were having trouble coming up with reliable rules. Finally, Penny proposed exposing it as an option so the user could specify the one they wanted. Cleve responded with something like "If you and I can't figure out which algorithm to use, our customers have no chance. So let's just pick the one that usually works well and not make them try guess."

ktpsns 5 hours ago |

Matlab inspired the scilab ecosystem, which is based on numpy, scipy, matplotlib, pandas. This was a major driver for the data science industry for a decade before AI kicked in and tensorflow, etc. was also built ontop of these libraries.

While I personally try to avoid contemporary matlab at any cost, the open source ecosystem is great and matlab would be my go-to tool if they would not exist.

cdavid 3 hours ago | |

scilab is not based on numpy/etc. However, matlab was certainly an inspiration for the scientific python stack in early 2000s. I myself started contributing to numpy and matplotlib by adding missing features I needed to move away from matlab in 2006 or so.

KenoFischer 10 hours ago |

I only met him twice, so I don't have much to say, but let me share Alan's message instead, since he knew him well: https://discourse.julialang.org/t/cleve-moler-rip/137235.

leopd 4 hours ago | |

I also barely knew Cleve directly, but his impact and insight was legendary. I got to work at The Mathworks early in my career, and the respect Cleve had was clearly deserved. Technically brilliant, but also with a keen foresight for where the industry was going and how to best serve it. RIP

scientism 6 hours ago |

MATLAB was used extensively during my electronics eng degree 20+ years ago. You could do pretty much about anything with it: signal processing, neural networks t, simulations, anything... It was what made me take an interest into programming. Sad day. RIP Cleve.

raverbashing 5 hours ago | |

Yes (and Simulink helped a lot)

I mean of course you can do them all without simulink but it was much easier

user_7832 9 hours ago |

IMO this deserves a black banner/bar. I genuinely had no idea a single guy was behind MATLAB (or that it was so old). His contribution has been significant, to say the least.

indianbunghole 37 minutes ago |

"Clever Mole" *ggggggg*

sblank 9 hours ago |

I was honored to have worked with Cleve at Ardent Computer. He ran the benchmark and demo group squeezing performance out of thin air.

Great mathematician and a wonderful human being. I never stopped learning when I was around him. thttps://blogs.mathworks.com/cleve/2013/11/25/the-ardent-tita...

newswasboring 7 hours ago |

I feel sad by this. I have a strong love hate relationship with MATLAB. I think that happens with anything you use for 15 years. But I have always respected the software and its professional quality documentation. On the business side he created kind of a perfect existence for himself. A profitable company which they have still kept private so they can focus on things they want to solve.

ktallett 9 hours ago |

How very sad. Whilst not my piece of software of choice, it is definitely still used by plenty to do cool work. I do think it will eventually be surpassed by Python and Julia but it still has it's place right now.

kenty 7 hours ago |

Amazing impact that person had. Although MATLAB probably kind of outdated these days as anything can be accomplished in Julia and Py and I remember deploying that software being deliberately made difficult by this being shareware. When I studied almost everybody ended up using MATLAB during their study and almost everybody ended up hating it when it came to publishing results and doing demonstrations.

bsoles 17 minutes ago | |

> Although MATLAB probably kind of outdated these days as anything can be accomplished in Julia and Py.

Literally every major brand car runs code built with MATLAB and Simulink. Same goes for every modern aircraft, space vehicle, etc. Far from being outdated.