more financial formulas

solver (2 examples)
1) take nominal rate (APR) and divide it by freq for year. (e.g., if compounds monthly, divide by 12). that is called the periodic effective rate.
2) calculate: (1 + PeriodicEffectiveRate)^NPER - 1. that is called the annual effective rate



quiz up to this point

next time:
back to invoice
pivottable and pivotchart

we got up to and including 15.

limitations of goal seek:
1) only fiddle with one cell
2) only "seek" for a specific value
3) cannot impose constraints

special tool, Goal Seek on steroids:
Solver

ch 8 if you have it, in the lab book for excel.
but i'll be going over it next time anyway.

Quiz 2

lecture

HW:
lecture book, exercise 2.9
start reading ch 3 in book.

index.html

how to copy local files to the remote machine, and vice versa

incorporating images in a web page
i used width and height attributes

i also "hotlinked"
that is not nice!
the web site might go down
they can take revenge by changing the image to something you don't want, embarrassing

how not to hotlink

equation for financial calculations
FV = PV * (1 + RATE) ^ NPER

we got up to and including example 9 in finance chapter

=3+A1
=SUM(), AVERAGE
quick intro to functions

WEB:
once you have successfully logged in
you need to create a folder called
public_html

then, you can create files inside that folder. i created hello.html


cs12.cs.qc.cuny.edu/~wajo6788/hello.html

note to self - it was called Invoice1.xlsx

Time value of money

money is worth more now than later

PV = present value
FV = future value

PV + PV * RATE
PV * ( 1 + RATE )

PV * ( 1 + RATE )
PV * ( 1 + RATE ) * ( 1+ RATE)
PV * ( 1 + RATE ) * ( 1+ RATE) *(1 + RATE)

FV = PV * (1 + RATE) ^ NPER




404 error
page does not exist

403 error
permissions not granted

absolute vs. relative refs

excel seems to be smart
it modifies rows as appropriate
so too, cols

we don't like "magic numbers"
we want to isolate assumptions

relative refs automatically adjust
absolute references stay in place

absolute refs: use $

A1 style - what we;ve seen so far
R1C1 style - row number, column number

[] in R1C1 style mean offsets

by default, when you NAME a cell, it names
it as an absolute reference

debugging tools
things go wrong

"bug"
http://en.wikipedia.org/wiki/Grace_Hopper
Grace Hopper
first computer bug

"evaluate formula" tool
"trace precedents" tool
"trace dependents" tool

way of figuring out what is going wrong

http://cs12.cs.qc.cuny.edu/~joshwaxman

your webpage will be:
http://cs12.cs.qc.cuny.edu/~wajo4672

host name: cs12.cs.qc.cuny.edu
username (all lower-case):
First 2 letters of last name followed by
First 2 letters of first name followed by
Last 4 digits of CUNYFirst ID#
password: 8 digits of CUNYFirst ID#

need a program to log on to this computer
WINSCP if you have a PC
Fugu if you have a Mac

If you Google Search
WinSCP download
winscp.net/eng/download.php

HW: Try to download and install WINSCP
try to login using your credentials

If you have a Mac, Fugu
http://cs12.cs.qc.cuny.edu/~xiuyi/fugu.html

HW: the next two exercises in ch 2 in lecture book about HTML
2.7-2.8

Really, all websites are numbers
IP addresses
DNS - domain name system
http://en.wikipedia.org/wiki/Domain_Name_System
a phone book for the internet

http://123.45.2.90/chase.com/thisisreal/gimmeyourfinancialinfo.htm

http://0xff.0xab.0xca.0xab/chase.com/login

http://chase.info/login
http://chase-banking.com/login

You could Google Chase

http://scamsite.ru/chase.com/login

domain starts at the :// and ends at the first slash
you can use this to detect many scams

domain, subdomain
domain is REALLY just the last 2 elements of what we've called the domain so far.
subdomain is before this.

eniac.cs.qc.cuny.edu/~svitak/cs12/

why is this important?
http://chase.com.scamsite.ru/login

Phishing email
besides the URLs, misspellings, will not know your name.

http://www.snopes.com/

Also, check out Amazon student

lecture

I haven't put up the assignments on Blackboard yet, so hold on to them.

For HW:
Ch 2 in lecture book, on HTML, exercises 2.4 to 2.6.


A list of hws so far:
1) binary conversions
2) lecture book, ch 1, review questions
3) lecture book, ch 2, exercises 2.1 to 2.3.
4) lecture book, ch 2, exercises 2.4 to 2.6.

http://www.w3schools.com/html/default.asp

early goal of HTML, they didn't stick to much: markup meaning, rather than formatting.

CSS - cascading style sheets





We finished "HTML Elements" on W3Schools

Excel
rows, col, cells
values
data types: number, text, logical, errors

formulas
always start =
operands can be values
operators such as +, -, /, *
order of operation
PEMDAS

Monday at 3:00 in adjunct room (A202?, right across from dept office)

lecture

algorithm - a recipe

search algorithms
Linear search vs. binary search
choose a good algorithm, because CPU speed can only go so far


Linear search - sequentially examine each element in collection, see if it is what you are looking for

int i = 0;
while(A[i] != 6)
{
i = i + 1;
}
if (A[i] == 6)
cout << "We found it at position " << i;
else
cout << "Sorry, we did not find it";

Analysis of Algorithms
Euler's rule
sum of:
1 + 2 + 3 ..... + n
(n+1) * (n/2) =
(n^2 + n) / 2
divide by n
about n
on the order of n
O(n)

What if the numbers are sorted?
we can use binary search.
is O(log n)
log base 2 of n

1 million elements in my collection
in linear search, about 1 million operations
in binary search, about 20 operations

Computers cannot do everything

http://www.claymath.org/millennium/

Traveling salesman problem
not solvable in amount of time we have
using algorithm i described


next quiz next wednesday

how to encode:
numbers
characters
now, pixels

picture element

2 color bitmap. L x W / 8
because only need 1 bit per pixel

16 colors
2^4 = 16
so we need four bits for each pixel
four bits = 1/2 byte
300 across x 200 down = 60,000 pixels
so, 30 bytes are necessary

256 colors.
2^8 = 256
so, need 1 byte per 1 pixel
60,000

24-bit bitmap = "True color" = 3 bytes per pixel
180,000
store RGB values
16,777,216 possible values

this was for .BMP files that you do this kind of mult to find the size

hexadecimal specification of color
#99 ff 00

RLE
run-length encoding
http://en.wikipedia.org/wiki/Run-length_encoding

GIF uses LZW encoding, which is a different encoding scheme. specifics, you don't need to know

lossless compression - GIF
don't lose info

lossy compression - JPG
loses info every time you save

raster vs. vector graphics
http://en.wikipedia.org/wiki/Raster_graphics
http://en.wikipedia.org/wiki/Vector_graphics

http://en.wikipedia.org/wiki/SVG