How differently should I use a flash with film camera?

I will be using flash with a film camera for the first time. I've some experience with on and off camera flash with digital camera and film camera for landscape pictures. Now I do not know what are the things I should be careful of when using a flash with film camera.

Some details:

1. Camera: Nikon F100
2. Flash: Nikon SB-600
3. Film: Portra 400 (Color), Neopan 400 (B&W)

What I am looking for are some tips and specific settings for using flash with a film camera. Also is matrix metering in F100 with TTL flash good enough for general purpose?

Confusion related to expectation

I was reading a paper related to minimaxity.

If $\hat{\theta}$ is the estimate of an unknown parameter $\theta$ and $l(\hat\theta-\theta)$ is the loss function they have mentioned $E_p$ is the mean of $l(\hat\theta-\theta)$ under distribution P. I didn't get this part. If $\hat\theta$ is an estimate and $\theta$ is the unknown parameter of a distribution P, then $\theta$ is fixed since it is the mean of the distribution P which is not known. So what is meant by expectation of $l(\hat\theta-\theta)$

Illustrator CS6 align objects keyboard shortcut

Is it possible to create a custom keyboard shortcut in Adobe Illustrator CS6 on OS X 10.8.5 to align and/or distribute objects (center/left/right/etc)? I know I can open the Align window, but I would like to apply the alignment with a shortcut.

Edit > Keyboard Shortcuts doesn't provide an option and it isn't clear to me how, if possible, to write my own in a keyboard shortcut file (e.g. /Users/user/Library/Preferences/Adobe Illustrator CS6 Settings/en_US/custom.kys).

Is the sparsity pattern of a linear system important for iterative (KSP) solvers?

Pretty much the question. Given a general sparse, non-symmetric (both numerically and structurally) matrix, how important is the sparsity pattern (i.e. row/column permutation of matrix/vector) for iterative solvers? I can see it becomes important for direct solvers (LU) or preconditioners (ILU) by directly affecting the number of fill-ins.

For iterative solvers, however, it seems that the most important part is the MatVec operation which does not seem to care about the actual matrix pattern. Is there some component that could be depended on the pattern that I'm not considering here?

How about in parallel? I suspect the pattern could become important in the way the matrix and vectors are distributed and thus determines the communication volume/overhead but would like to see other thoughts and inputs.

I'm asking this both in general and also regarding PETSc's KSP solvers.

Project Euler 39: Integer right triangles

I just finished Project Euler 39:

If p is the perimeter of a right angle triangle with integral length sides, {a, b, c} … For which value of p ≤ 1000, is the number of solutions maximised?

I'm pretty satisfied with my solution. I derive the formula for the hypotenuse as follows:

\begin{align} a + b + c &= p \tag{Def. perimeter}\\ b + c &= p - a \tag{2}\\ \\ a^2 + b^2 &= c^2 \tag{Pythagorean}\\ a^2 &= c^2 - b^2 \\ a^2 &= (c - b)(c + b) \\ a^2 &= (c - b)(p - a) \tag{from (2)} \\ \frac{a^2}{p - a} &= c - b \tag{7} \\ \\ (c - b) + (c + b) &= \frac{a^2}{p - a} + (p - a) \tag{from (7) and (2)}\\ 2c &= \frac{a^2}{p - a} + \frac{(p - a)^2}{p - a} \\ 2c &= \frac{a^2 + (p - a)^2}{p - a} \\ c &= \frac{a^2 + (p - a)^2}{2\ (p - a)} \end{align}

Any optimization would be appreciated.

from timeit import default_timer as timer

start = timer()
def find_pythagorean_triples(perimeter):
count = 0
for a in range(3, perimeter / 2 - 1): # triangle inequality
c = (a**2 + (perimeter - a)**2) / (2*(perimeter - a)) # derived formula
b = (c**2 - a**2)**0.5
if b.is_integer() and a + b + c == perimeter:
count += 1
return count

def find_most_solutions_upto(limit):
data = {"most": 0, "num": 0}
for p in range(limit/2, limit + 1): # scale upwards
if find_pythagorean_triples(p) > data['most']:
data['most'] = find_pythagorean_triples(p)
data['num'] = p
return data['num']

ans = find_most_solutions_upto(1000)
elapsed_time = (timer() - start) * 1000 # s --> ms

print "Found %d in %r ms." % (ans, elapsed_time)


How to create a new properties to $node (or$user and so on)

I would like to add a properties to the node object (or user, file, etc).

I know that I can use a field, but it could be useful to do this.

Which is the way?

Thanks, Sergio

Is Parvati mentioned in the Vedas?

The pretext of this question is Sati(from Swayambhuva Manvantra) is mentioned in the Vedas, but Parvati(of the current Vaivasvata Manvantra) is not. Correlating the absence of characters who come in the later Manvantra(after Swayambhuva manvantra) with the perceived time of compilation the Vedas(In the beginning of each Kalpa) it seems like the timelines do add up. The aim of the question is to ascertain that no characters who come in later Manvantras find mention in the Vedas(specifically Rig Vedas), except in cases where the Vedas may predict the arrival of an Avatar or other prominent characters in later Manvantras.

With the above given pretext, my questions are the following.

1. Is it true that the name Parvati does not appear explicitly in the Vedas? American Sanskrit scholar Edward Hopkins notes that While the word Umā appears in earlier Upanisads, the earliest known explicit use of the name Pārvatī occurs in late Haṃsa Upanishad (Yoga / Shukla Yajurveda) [1]. Does this mean that Yajurveda was compiled much later than the Rig Veda?

2. Does any character in Ramayana/Mahabharatha find mention in Vedas?

3. Since the first written collection of Rig Veda was compiled by Rishi Vyasa, was it updated to include characters in the time between the first Manvantra and time of compilation?

4. https://en.wikipedia.org/wiki/Parvati

use areFoo or isFoo?

I have never seen the use of "are" for boolean methods, but the use of "is" is very common.

When I want to use "are" is usually because I am passing multiple variables, or a list of objects.

I suppose I could rationalize my list of objects or multiple variables as one thing, such as "isSetupParametersValid", but that would still be plural.

Is the lack of use of "are" in boolean methods, simply an arbitrary convention or a side-effect of using best practices. If it's a side-effect of best-practices, which ones?

Note: for non-native English speakers "is" refers to a singular object, "are" refers to plural/multiple objects

Can I shop an unfinished novel?

I've been writing a novel that addresses some very current themes. My belief is that if I can get it out there quickly, it will succeed well. I'm working on it frantically, but will agents consider representing a work in progress? At what point is it close enough?

What can I do with Spirit Magic?

I have a player who wants to take Spirit evocation, as an idea, but neither of us are sure practically on what sort of spells it would let him evoke.

What does Spirit Magic let my player's character do? Are there examples?

We're playing a very investigative game, and both combat and non-combat magic is relevant.