I am trying to do an assignment in JES a student jython program. I need to convert our student number taken as a string input variable to pass through our function i.e.
def assignment(stringID) and convert it into integers. The exact instructions are:
Step 1
Define an array called id which will store your 7 digit number as integers (the numbers you set in the array does not matter, it will be over written with your student number in the next step).
Step 2 Your student number has been passed in to your function as a String. You must separate the digits and assign them to your array id. This can do this manually line by line or using a loop. You will need to type cast each character from stringID to an integer before storing it in id.
I have tried so many different ways using the int and float functions but I am really stuck.
Thanks in advance!
>>> a = "545.2222"
>>> float(a)
545.22220000000004
>>> int(float(a))
545
I had to do some jython scripting for a websphere server. It must be a really old version of python it didn't have the ** operator or the len() function. I had to use an exception to find the end of a string.
Anyways I hope this saves someone else some time
def pow(x, y):
total = 1;
if (y > 0):
rng = y
else:
rng = -1 * y
print ("range", rng)
for itt in range (rng):
total *= x
if (y < 0):
total = 1.0 / float(total)
return total
#This will return an int if the percision restricts it from parsing decimal places
def parseNum(string, percision):
decIndex = string.index(".")
total = 0
print("decIndex: ", decIndex)
index = 0
string = string[0:decIndex] + string[decIndex + 1:]
try:
while string[index]:
if (ord(string[index]) >= ord("0") and ord(string[index]) <= ord("9")):
times = pow(10, decIndex - index - 1)
val = ord(string[index]) - ord("0")
print(times, " X ", val)
if (times < percision):
break
total += times * val
index += 1
except:
print "broke out"
return total
Warning! - make sure the string is a number. The function will not fail but you will get strange and almost assuredly, useless output.
Related
I am new to Scala programming, I want to generate random number with 15 digits, So can you please let share some example. I have tried the below code to get the alpha number string with 10 digits.
var ranstr = s"${(Random.alphanumeric take 10).mkString}"
print("ranstr", ranstr)
You need to pay attention to the return type. You cannot have a 15-digit Int because that type is a 32-bit signed integer, meaning that it's maximum value is a little over 2B. Even getting a 10-digit number means you're at best getting a number between 1B and the maximum value of Int.
Other answers go in the detail of how to get a 15-digits number using Long. In your comment you mentioned between, but because of the limitation I mentioned before, using Ints will not allow you to go beyond the 9 digits in your example. You can, however, explicitly annotate your numeric literals with a trailing L to make them Long and achieve what you want as follows:
Random.between(100000000000000L, 1000000000000000L)
Notice that the documentation for between says that the last number is exclusive.
If you're interested in generating arbitrarily large numbers, a String might get the job done, as in the following example:
import scala.util.Random
import scala.collection.View
def nonZeroDigit: Char = Random.between(49, 58).toChar
def digit: Char = Random.between(48, 58).toChar
def randomNumber(length: Int): String = {
require(length > 0, "length must be strictly positive")
val digits = View(nonZeroDigit) ++ View.fill(length - 1)(digit)
digits.mkString
}
randomNumber(length = 1)
randomNumber(length = 10)
randomNumber(length = 15)
randomNumber(length = 40)
Notice that when converting an Int to a Char what you get is the character encoded by that number, which isn't necessarily the same as the digit represented by the Int itself. The numbers you see in the functions from the ASCII table (odds are it's good enough for what you want to do).
If you really need a numeric type, for arbitrarily large integers you will need to use BigInt. One of its constructors allows you to parse a number from a string, so you can re-use the code above as follows:
import scala.math.BigInt
BigInt(randomNumber(length = 15))
BigInt(randomNumber(length = 40))
You can play around with this code here on Scastie.
Notice that in my example, in order to keep it simple, I'm forcing the first digit of the random number to not be zero. This means that the number 0 itself will never be a possible output. If you want that to be the case if one asks for a 1-digit long number, you're advised to tailor the example to your needs.
A similar approach to that by Alin's foldLeft, based here in scanLeft, where the intermediate random digits are first collected into a Vector and then concatenated as a BigInt, while ensuring the first random digit (see initialization value in scanLeft) is greater than zero,
import scala.util.Random
import scala.math.BigInt
def randGen(n: Int): BigInt = {
val xs = (1 to n-1).scanLeft(Random.nextInt(9)+1) {
case (_,_) => Random.nextInt(10)
}
BigInt(xs.mkString)
}
To notice that Random.nextInt(9) will deliver a random value between 0 and 8, thus we add 1 to shift the possibble values from 1 to 9. Thus,
scala> (1 to 15).map(randGen(_)).foreach(println)
8
34
623
1597
28474
932674
5620336
66758916
186155185
2537294343
55233611616
338190692165
3290592067643
93234908948070
871337364826813
There a lot of ways to do this.
The most common way is to use Random.nextInt(10) to generate a digit between 0-9.
When building a number of a fixed size of digits, you have to make sure the first digit is never 0.
For that I'll use Random.nextInt(9) + 1 which guarantees generating a number between 1-9, a sequence with the other 14 generated digits, and a foldleft operation with the first digit as accumulator to generate the number:
val number =
Range(1, 15).map(_ => Random.nextInt(10)).foldLeft[Long](Random.nextInt(9) + 1) {
(acc, cur_digit) => acc * 10 + cur_digit
}
Normally for such big numbers it's better to represent them as sequence of characters instead of numbers because numbers can easily overflow. But since a 15 digit number fits in a Long and you asked for a number, I used one instead.
In scala we have scala.util.Random to get a random value (not only numeric), for a numeric value random have nextInt(n: Int) what return a random num < n. Read more about random
First example:
val random = new Random()
val digits = "0123456789".split("")
var result = ""
for (_ <- 0 until 15) {
val randomIndex = random.nextInt(digits.length)
result += digits(randomIndex)
}
println(result)
Here I create an instance of random and use a number from 0 to 9 to generate a random number of length 15
Second example:
val result2 = for (_ <- 0 until 15) yield random.nextInt(10)
println(result2.mkString)
Here I use the yield keyword to get an array of random integers from 0 to 9 and use mkString to combine the array into a string. Read more about yield
i am using memoization to save the last calculated values of fibonacci numbers in a dictionary. Since (i suppose) that we don't need all of the values that were previously calculated in our dictionary so, i want to delete them. specifically i only want to keep only the last two calculated fibonacci numbers, is there a way to do it?
import sys
sys.setrecursionlimit(10000)
cache = {}
def fib(n):
if n in cache:
return cache[n]
elif n <= 2:
value = 1
else:
value = fib(n-1) + fib(n-2)
cache[n] = value
return value
print(fib(1000))
ok i found it.
cache = {}
for x in range(1, 1000001):
if x > 4:
cache.pop(x-3, x-4)
if x <= 2:
value = 1
cache[x] = value
else:
value = cache[x - 1] + cache[x - 2]
cache[x] = value
print(value)
In Apple Numbers the MOD function differs from Swift (in the German version it is REST.
In Numbers:
4,37937=MOD(−1,90373;6,2831)
versus
In swift 3:
let rem1: Double = -1.90373
let rem = rem1.truncatingRemainder(dividingBy: 6.28318530717959)
print(rem)
Prints: -1.90373
What I am doing wrong?
I found the solution:
let rem1: Double = -1.90373
let rem = rem1 - 6.28318530717959 * floor(rem1 / 6.28318530717959)
print(rem)
will do the same like Apples Numbers MOD is doing.
a % b performs the following and returns remainder
a = (b x some multiplier) + remainder
some multiplier is the largest number of multiples of b that will fit inside a.
e.g. some integer constant [0...]
The documentation provides the following as an example
Inserting -9 and 4 into the equation yields:
-9 = (4 x -2) + -1
giving a remainder value of -1.
The sign of b is ignored for negative values of b. This means that a
% b and a % -b always give the same answer.
In my program I am using Bigdecimal to truncate numbers and storing them in a variable. Eg. 123.456789 is getting displayed as 123.45.Further I am trying to find the absolute of the numbers.The problem arises here i.e - 123.45 should appear as 123.45 but it's appearing as 123.4589Egh.Can someone please help as to how can I find absolute of numbers.
var diff1=BigDecimal(diff).setScale(2, BigDecimal.RoundingMode.HALF_UP).toDouble
var bigdec=abs(diff1)
Try taking inputs for 10-15 numbers in an array (in diff variable)
Uhm, I'm not sure what your problem is, but for me this works fine:
val diff = -123.456789
var diff1 = BigDecimal(diff).setScale(2, BigDecimal.RoundingMode.DOWN).toDouble
var bigdec = Math.abs(diff1)
println(bigdec) // 123.45
Note that if you want 123.45 instead of 123.46 you have to change your rounding mode.
Taking in an array doesn't change anything, although you need to make a def and map over the array now when rounding - as you cannot call the BigDecimal apply function on an Array:
// generates an Array of 20 elements with random doubles from 0 to 200
val diff = Array.fill(20)(math.random).map(_ * 200)
.map { num => // using this map function to make some negatives
if (num < 100) num * -1
else num
}
def round(double: Double) = BigDecimal(double)
.setScale(2, BigDecimal.RoundingMode.HALF_UP)
.toDouble
var absolute = diff.map(num => Math.abs(round(num)))
Does the above code reflect what you are doing? If so, for var absolute I am getting an Array[Double] with positive numbers and only 2 decimal places.
I want to convert the decimal number 27 into binary such a way that , first the digit 2 is converted and its binary value is placed in an array and then the digit 7 is converted and its binary number is placed in that array. what should I do?
thanks in advance
That's called binary-coded decimal. It's easiest to work right-to-left. Take the value modulo 10 (% operator in C/C++/ObjC) and put it in the array. Then integer-divide the value by 10 (/ operator in C/C++/ObjC). Continue until your value is zero. Then reverse the array if you need most-significant digit first.
If I understand your question correctly, you want to go from 27 to an array that looks like {0010, 0111}.
If you understand how base systems work (specifically the decimal system), this should be simple.
First, you find the remainder of your number when divided by 10. Your number 27 in this case would result with 7.
Then you integer divide your number by 10 and store it back in that variable. Your number 27 would result in 2.
How many times do you do this?
You do this until you have no more digits.
How many digits can you have?
Well, if you think about the number 100, it has 3 digits because the number needs to remember that one 10^2 exists in the number. On the other hand, 99 does not.
The answer to the previous question is 1 + floor of Log base 10 of the input number.
Log of 100 is 2, plus 1 is 3, which equals number of digits.
Log of 99 is a little less than 2, but flooring it is 1, plus 1 is 2.
In java it is like this:
int input = 27;
int number = 0;
int numDigits = Math.floor(Log(10, input)) + 1;
int[] digitArray = new int [numDigits];
for (int i = 0; i < numDigits; i++) {
number = input % 10;
digitArray[numDigits - i - 1] = number;
input = input / 10;
}
return digitArray;
Java doesn't have a Log function that is portable for any base (it has it for base e), but it is trivial to make a function for it.
double Log( double base, double value ) {
return Math.log(value)/Math.log(base);
}
Good luck.