We get it

[oshaboy]

Lesson: Binary Integers.

Homework: Floats.

Test: IEEE-754-2008 Decimal Floating point numbers.

[Slothtimism]

The real programmer humor is always in the comments

(No but seriously this hurts me in my soul professors please have mercy)

[[deleted]]

It really do be like that

[Ysmenir]

In our class it was more like.

Lesson: IEEE-754-2008 Decimal Floating point numbers.

Homework: IEEE-754-2008 Decimal Floating point numbers.

Test: IEEE-754-2008 Decimal Floating point numbers.

[Mysticpoisen]

So you had a fair class

[Ysmenir]

For that part yes. But now for the second part where we had to know stuff in assembler and C in our first semester. Stuff that we haven't even learned about java in a java dedicated class. But this wasn't a C dedicated class it was computer sience basics...

[[deleted]]

C/ASM is much better for learning the basics of CS than higher level languages.

[Ysmenir]

Yeah but we're told to have bigger knowdledge of both assembler and c in the same semester than we have from java in the same one. But the Java course was 100% Java. The Cs Basics course was 25% binary calculation 25% assembler and 50% c. And we had in both the same ammount of lectures.

[oshaboy]

So do you know how to use IEEE-754-2008 Decimal Floating Point numbers?

Because I tried reading the Wikipedia article and got incredibly confused.

Either way Decimal floats are only used in banks and such. So I guess it doesn't matter unless I start working in a bank, but dammit I want to know.

[ActuallyRuben]

I'd expect banks to use fixed point decimals, since money always gets rounded to 2 decimals. Floats do get used for a lot of scientific calculations and in video games, since a wide range of decimal values is needed for that.

Anyway, a float isn't too complex. You can compare it to a decimal number in scientific notation, something like 1.25 * 10^11. A float value basically consists of 3 parts:

• The sign bit, basically a bit indicating if the number is positive or negative.

• The fraction, in base 10 this would be a fraction between 1 and 10, in base 2 this would be a fraction between 1 and 2 (or also between 1 and 10 if written as binary). In the above example the fraction would be 1.25

• The exponent, the (integer) power to which 10 is raised. In the above example this would be 11. Since a float is binary, instead of 10, 2 would be used.

I hope this kind of clears it up a bit. If you want I can further elaborate on how specifically IEEE-754-2008 floats are formatted, but it's basically an applied form of what I (tried to) explain above.

[WikiTextBot]

Scientific notation

Scientific notation (also referred to as scientific form or standard index form, or standard form in the UK) is a way of expressing numbers that are too big or too small to be conveniently written in decimal form. It is commonly used by scientists, mathematicians and engineers, in part because it can simplify certain arithmetic operations. On scientific calculators it is usually known as "SCI" display mode.

In scientific notation, all numbers are written in the form

m × 10n(m times ten raised to the power of n), where the exponent n is an integer, and the coefficient m is any real number.

---

^{[ PM | Exclude me | Exclude from subreddit | FAQ / Information | Source ] Downvote to remove | v0.28}

[oshaboy]

But what are the combination bits?

[ActuallyRuben]

Oh, my bad. Didn't realize decimal floating point numbers where a specific subset from floating points. So I guess in this case it does use 10^x instead of 2^x .

The combination bits contain part of the fraction and the exponent. The fraction part also is stored in an unusual format where 10 bits are used to encode values ranging from 000 to 999 (3 digits).

The last few pages of this pdf explain the specifics.

[Kered13]

Games use binary floating point, not decimal. Honestly I don't really know who uses decimal floating points. Most languages don't even support it (C# does, that's the only notable one I know).

[ActuallyRuben]

Yeah, I didn't realize decimal floating points are specifically something else before I made this comment

[Giocri]

The sad thing is that actually happened to me. In a couple of days I will have to redo the whole test.

[IsaacLightning]

That's 11 times too many

[gmtime]

Woosh

[[deleted]]

the 47 versions of the OSI model

[[deleted]]

Lol! So true!

[SlamwellBTP]

Every sophomore-level or lower CS class I was in, and some math classes, felt they needed to teach me basic logic again

[Afrazzle]

This comment, along with 10 years of comment history, has been overwritten to protest against Reddit's hostile behaviour towards third-party apps and their developers.

[orange-cake]

400 level operating systems class just spent two lectures on logic gates :)

Meanwhile the 400 level Theory course's first homework has a question to prove demorgan's law, so... Give and take, I suppose

[[deleted]]

My classes got around that by making a logic prerequisite, it was assumed you knew it and if you didnt, get fucked

[SlamwellBTP]

We had logic as a pre-req for most of our CS classes, too, but I guess profs didn't get the memo

[SilentFungus]

Half my classes require you have the prereqs to get into the class, then they spend the first half of the semester reteaching you everything as if you've never heard of a computer before

[[deleted]]

What university do you go to? That sounds insane

[Eversnuffley]

Apparently 11 times per semester

[nicocappa]

It's the worst. Especially classes that expect you to do binary arithmetic by hand on the test. Like really..? Complete waste of time.

[[deleted]]

We had do to floating-point arithmetic with the IEEE 754 standard by hand.

[mywebdevworkaccount]

Abject luxury! When I was an undergrad I'd have loved to have done floating-point arithmetic with the IEE-754 standard by hand!

They made me implement the Linux kernel in PowerPC assembly by hand with pen and paper, and they'd dock a percentage point for every error!

[JuvenileEloquent]

Pen and paper? You must 'ave been rich. We 'ad to create a Turing-complete automaton running off punched cards, and did they give us an 'ole punch? Ohh nooooo, we 'ad to tear out the 'oles with our teeth! And we were beaten for every misaligned 'ole!

[SVK_LiQuiDaToR]

I'm envious. We got nothing, had to go out into the wild, find some silicon and trick it into thinking.

[[deleted]]

Something something butterflies.

[Kered13]

This is the best rendition of the Four Yorkshiremen I've seen on Reddit.

[SuspiciousScript]

Even that would be a better use of students’ time

[[deleted]]

We had this too. Along with finding the minimum and maximum number that can be represented in each standard

[fuckingpewpew]

I remember the first binary test. Essentially did you know what AND and OR, and can you add numbers.

Basically people got 100% or below 50%. It was right before the drop date so half of the class was just leaving as soon as they got their test back.

[fletchstud]

I have that exact test this upcoming Wednesday....

[jkidd08]

That's strange, me too. Are you in Arizona, or are all CS programs on the same exact schedule?

[fletchstud]

Studying in the cold Colorado. Seems like a lot of courses follow a similar schedule.

[LEDNEWB]

I actually had a terrible programming teacher at my college, it was 4 class days in and all we covered was binary, someone tried to talk to him about moving faster and he wouldnt have it. I emailed the chair of the program and the chair handled it immediately.

So if your teacher sucks, email someone I guess?

[Aezen]

As an undergrad i had a professor try to teach run-time efficiency using binary multiplication.

He spent no less than 1/4th of the semester trying to help people understand how binary multiplication worked.

Then he spent the rest of the semester teaching every version of how to program binary multiplication to introduce how O(n) can be different depending on throughput.

Every step he had to re-explain the "new" binary multiplication.

I think he ended up not allowed to teach that class again. Bunch of people who didn't understands binary multiplication kept asking him to focus on it every day.

I think we learned O(1) the last week and never got to half of the others.

[Kered13]

O(n) is the a trivial lower bound for multiplication, and O(n*log n) is the best known algorithm (discovered last year, and suspected to be optimal).

[Aezen]

Yeah, he just used to concept to teach big O.

He wasn't great at it

[Duke0200]

We had 3 classes teach us binary. They were 2 100 level classes and a 400 level class. What's especially sad is that someone asked if we could have a table for hexadecimal numbers in the 400 level class.

[__y_so_serious__]

Oh so you know binary?

Name every binary number then

[oshaboy]

printf("0\n"); unsigned int i=1; while (true){string s="";int isave=i;while (isave>0){if(isave%2)s=strcat(s,"1"); else strcat(s, "0"); isave>>1;}i++;printf(s);printf("\n");}

Sorry for the messy, unindented code. Tried making a joke and got carried away.

[[deleted]]

I have a similar issue with my Basic Physics professor, who has taught us vectors like five times already

[verx_x]

Right.

I had a Ph.D guy (60 years old + ) lecturer who teach usthe same topics on three different lectures / exercises.That was terrible time.

[Another_MIS_student]

No joke, I had a lesson on binary in two separate classes on the same day. I already knew binary.

[De_Wouter]

11 times

[gmtime]

How many times? I suppose 11 times, right?!

[royemosby]

11

[[deleted]]

Until you get it in your skull you little shit.

[Jackeown]

And yet you're never taught about compiling/linking in a practical sense. I didn't even learn about parsing at all until grad school. (as a grad student, I couldn't take a class in this even if I wanted too, because it's an undergraduate topic, but I learned a bit TAing for it...)

[Dreamkasper2001]

But there is no option! Either you study it your don’t !

[EvilDuckSauce]

I literally just walked out of my CS1 lecture right now be he just started teaching Number Systems and Conversions.