Pith.
It’s funny (and deeply on brand) how this particular moment feels like the real death knell, after there’s been occasion to declare Tumblr dead pretty much every six months since 2013 for one reason or another. (Closing the NY office earlier this year was the one that sealed it for me.) But for whatever reason, this feels like time for a bit of closure.
Thank you for everything, Tumblr. You got me through my 20′s, introduced me to some of the most amazing people I’ve ever met (and the most amazing people I’ve never met), helped find me a career, exposed me to perspectives that were missing from my worldview, and kept me company so many times in so many ways.
I hope Tumblr continues, in some form, to keep holding space for the countless voices that it does so for as long as the internet is turned on. I’m proud as hell to have been a part of that.
via katembowen
While I’m here, this has been in my drafts for almost a decade. I like it a lot and kept meaning to write about it. I never did. I think you’re ready for it now. Here you go.
What is mba programs in India?
This is not a Jeopardy! tumblog.
Anonymous asked:
hey how long will the infographic be checked? waiting for your responce.
Until it breaks out of check or concedes.
Hilary Fitzgerald Campbell, an old-school chart lover and member of the community (she was a contributor to I Love Charts: The Book!) has just released her first book of cartoons!
The book is titled Breaking Up Is Hard To Do, But You Could've Done Better, and it is a compilation of painfully funny (and true, and anonymous) stories and the cartoons they inspired.
It’s open for preorder and looks absolutely delightful, so please do check it out.
An I LOVE CHARTS EXCLUSIVE first look at a chart from Feminist Fight Club: An Office Survival Manual (for a Sexist Workplace) — the new book from our good friend Jessica Bennett, New York Times writer and former Tumblr editor.
The book — a battle manual for fighting sexism at work — hits shelves Sept. 13, with illustrations from Saskia Wariner and Hilary Fitzgerald Campbell.
Preorder your copy today!
In trying to understand sheaves, topology, open sets, chain complexes, kernel( ∂) ÷ image( previous(∂)), algebraic topology, cokernel, fibration, base space & total space, étale maps,, and some other stuff, I found I needed to think more simple, dumb thoughts, carefully about
- partial functions
- codomain vs image
- the Cartesian definition of a function
- monotonicity / injective / horizontal line test / multimaps
Sometimes the image of ƒ might take up less than the entire range defined. Sine from ℝ to ℝ is an example; the height of the wave never goes above 1 or below −1 (since the function is defined, for convenience, on radius 1 “unit”. Whether that be millimetres or kilometres is left unstated, to make theory easier). Square root from ℝ to ℝ is an example of both: neither can we assign values to negative inputs (so √ is only a “partial function”) — nor will we get negative outputs (unless we violate the Cartesian definition of function, or at least tweak it). (it’s in this sense that ℂ is a “better” number system: any root √ ∛ ∜ , if defined to accept & return ∋ ℂ , will work on any input, and, we will actually use all of the output values we allotted ourselves (so image won’t be smaller than range≝codomain. Since ℂ is kind of circular, roots just end up changing how many angles θ you go around the unit exp(√−1 • θ). Look up the power/log/exponent rules and you’ll see what I mean. ℂ numbers also have a length but √ does the same thing to that, that it did to the ±-only ℝ numbers. And it’s a (positive-only) length, so no patial-function crap or range/image mismatch there. ). ker ( ƒ ) ≝ ƒ⁻¹(1)
Let ƒ be a function from X to Y. The preimage or inverse image of a set B ⊆ Y under ƒ is the subset of X defined by
The inverse image of a singleton, denoted by ƒ−1[{y}] or by ƒ−1[y], is also called the fiber over y or the level set of y. The set of all the fibers over the elements of Y is a family of sets indexed by Y.
Source: Wikipedia
