I am printing 2d arrays to the node terminal window but the width causes them to wrap across multiple lines. How can I change the width of the node print area? This is not solved by changing the terminal window columns or rows. https://i.stack.imgur.com/XCWTT.png. Update: The problem is the printing of an array with node. If I print one string it will print a longer width so how do I change how node is giving arrays a default width of some kind regardless of number of elements?
For example:
console.log([1,2,3,4,5,6,7,8,9,10]);
will print
[
1, 2, 3, 4, 5,
6, 7, 8, 9, 10
];
Instead of putting it all on one line in node.
If your purpose is to visualize the two dimensional matrix, you may use console.table as in example below
a = [[1, 3, 3, 4], [2, 7, 9, 12]];
console.table(a)
the output is as below
Related
#!/usr/bin/python
numbers = [1, 2, 3, 5, 6, 7]
clean = numbers.insert(3, 'four')
print clean
# desire results [1, 2, 3, 'four', 5, 6, 7]
I am getting "None". What am I doing wrong?
Mutating-methods on lists tend to return None, not the modified list as you expect -- such metods perform their effect by altering the list in-place, not by building and returning a new one. So, print numbers instead of print clean will show you the altered list.
If you need to keep numbers intact, first you make a copy, then you alter the copy:
clean = list(numbers)
clean.insert(3, 'four')
this has the overall effect you appear to desire: numbers is unchanged, clean is the changed list.
The insert method modifies the list in place and does not return a new reference. Try:
>>> numbers = [1, 2, 3, 5, 6, 7]
>>> numbers.insert(3, 'four')
>>> print numbers
[1, 2, 3, 'four', 5, 6, 7]
The list.insert() operator doesn't return anything, what you probably want is:
print numbers
insert will insert the item into the given list. Print numbers instead and you'll see your results. insert does not return the new list.
I would like to loop a list to find the mean for a specific window.
What I mean by this is for example:
num_list=[1,2,3,4,5]
window=3
Thus, I would find the mean for [1,2,3] , [2,3,4] and [3,4,5].
How I approached this was as the following:
average_list=[]
first_list=num_list[0:window]
def mean(data):
n=len(data)
mean=sum(data)/n
return mean
for i in first_list:
first_value=mean(i)
average_list.append(first_value)
I am not quite sure how to incorporate the other two lists without typing it individually. Any help would be greatly appreciated!!
You can use list comprehension to iterate num_list taking slices of length window.
Try this:
mean_lst = [sum(num_list[i:i+window])/window for i in range(len(num_list)-window + 1)]
Result is
[2.0, 3.0, 4.0]
Here's the most obvious solution to your problem:
for i in range(list_len-window+1):
average_list.append(mean(num_list[i:i+window]))
It does work properly, but it isn't optimal. Consider num_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] and window = 5. Using obvious method, the code will first calculate the sum of [1, 2, 3, 4, 5], then divide by 5, then it will calculate the sum of [2, 3, 4, 5, 6], then divide by 5, and so on.
This code is clearly doing a lot more calculations than it needs to. An optimal way would be to calculate the mean of first window and then for calculating mean of every consecutive window remove the first_element_of_previous_window/window_size (1/5 for 2nd window) and add last_element_of_current_window/window_size (6/5 for 2nd window) to the mean of previous window. This approach avoids a lot of unnecessary calculations.
Code Implementation:
prev_mean = mean(num_list[:window])
average_list = [prev_mean]
for i in range(1, list_len-window+1):
prev_mean -= num_list[i-1] / window
prev_mean += num_list[i+window-1] / window
average_list.append(prev_mean)
I want to just understand why the below code is not very good at removing duplicates:
numbers = [4, 4, 4, 10, 10, 10, 20, 20, 2]
for duplicates in numbers:
numbers.count(duplicates)
if numbers.count(duplicates) > 1:
numbers.remove(duplicates)
numbers.sort()
print(numbers)
The final output is: [2, 4, 10, 10, 20]
This could just be a fundamental error in my understanding of the methods used, but I would like to know what is wrong here.
PS. I'm aware I could do an easier version of this code posted below, but I am just curious.
Easier version of above code:
numbers = [4, 4, 4, 10, 10, 10, 20, 20, 2]
unique_list = []
for duplicates_check in numbers:
if duplicates_check not in unique_list:
unique_list.append(duplicates_check)
unique_list.sort()
print(unique_list)
Thanks in advance for your help!
Modifying the list as you're iterating over it is a bad idea (since the loop gets "confused" about which index it's on).
Since you're sorting the numbers in the end, you apparently don't care about the order.
Just do
numbers = sorted(set(numbers))
– that is, convert the numbers to a set; sets can only contain each element once, then use sorted() to sort the set into a new list.
If you would care about the order,
def unique_in_order(iterable):
seen = set()
for item in iterable:
if item not in seen:
seen.add(item)
yield item
numbers = list(unique_in_order(iterable))
is your recipe.
I have these variables:
X = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
Y = (1, 5, 4, 9, 7, 8, 12, 20, 9, 7, 4, 1, 1, 2, 1, 1)
and I want to do a graphic with two visible partitions (X from 1 to 8 and X from 9 to 16). So, I set one dimension X and two expressions IF (X <= 8,Y) and IF (X > 8,Y). It works well and I got this:
Basic graphic
Now I want to include the linear trend line. But, after click in the proper option in the expressions tab, I got this:
Graphic with trend lines
which is not a good thing to see. I wished something like this:
Wished graphic with trend lines
Anyone knows how can I get a graphic like this last picture?
Many thanks in advance.
If you want manually to calculate the linear Regression you have to use these functions LINEST_B and LINEST_M like this:
linest_M(total aggr(Y,X),X)*X+ linest_b(total aggr(Y,X),X)
but with some modifications because you split your expressions.
Here is an example with your data set:
Here is the whole file
from Qliks' help
A=list(range(1,121))
for i in A:
A.remove(i)
print(A)
Shouldn't it be empty? I really don't get this..
You typically don't want to modify lists you're iterating over because you will get weird results like what you're running into.
You have a list of numbers, 1-121. You remove the first one, everything shifts down in memory so 2 is now in the zeroeth position. Do range 2-122 and you'll get only odd numbers.
x = [1, 2, 3, 4, 5, 6]
for i in x:
x.remove(i)
#first time through x = [2, 3, 4, 5, 6]
# ^ i is still pointing here though and the next time
# through it will be pointing at 3 (i = 2)