Let's say i have two relation arrays of a user's daily buy and sell.
how do i iterate through both of them using .each and still let the the longer array run independently once the shorter one is exhaused. Below i want to find the ratio of someone's daily buys and sells. But can't get the ratio because it's always 1 as i'm iterating through the longer array once for each item of the shorter array.
users = User.all
ratios = Hash.new
users.each do |user|
if user.buys.count > 0 && user.sells.count > 0
ratios[user.name] = Hash.new
buy_array = []
sell_array = []
date = ""
daily_buy = user.buys.group_by(&:created_at)
daily_sell = user.sells.group_by(&:created_at)
daily_buy.each do |buy|
daily_sell.each do |sell|
if buy[0].to_date == sell[0].to_date
date = buy[0].to_date
buy_array << buy[1]
sell_array << sell[1]
end
end
end
ratio_hash[user.name][date] = (buy_array.length.round(2)/sell_array.length)
end
end
Thanks!
You could concat both arrays and get rid of duplicated elements by doing:
(a_array + b_array).uniq.each do |num|
# code goes here
end
Uniq method API
daily_buy = user.buys.group_by(&:created_at)
daily_sell = user.sells.group_by(&:created_at
buys_and_sells = daily_buy + daily_sell
totals = buys_and_sells.inject({}) do |hsh, transaction|
hsh['buys'] ||= 0;
hsh['sells'] ||= 0;
hsh['buys'] += 1 if transaction.is_a?(Buy)
hsh['sells'] += 1 if transaction.is_a?(Sell)
hsh
end
hsh['buys']/hsh['sells']
I think the above might do it...rather than collecting each thing in to separate arrays, concat them together, then run through each item in the combined array, increasing the count in the appropriate key of the hash returned by the inject.
In this case you can't loop them with each use for loop
this code will give you a hint
ar = [1,2,3,4,5]
br = [1,2,3]
array_l = (ar.length > br.length) ? ar.length : br.length
for i in 0..array_l
if ar[i] and br[i]
puts ar[i].to_s + " " + br[i].to_s
elsif ar[i]
puts ar[i].to_s
elsif br[i]
puts br[i].to_s
end
end
Related
I have a loop that adds numbers in groups of a certain number which can be inputted by the user.
no_reps = #trial.number_of_repetitions
I'm looking to input a random number between one and the no_reps variable in groups of no_reps variable.
Current the r.treatment_index = SecureRandom.random_number(1..no_reps) isn't putting in unique numbers. The values match the range, but aren't unique per in_groups_of.
#trial.repetitions.in_groups_of(no_reps).each_with_index do |a, i|
a.each do |r|
r.repetition_index = i + 1
r.treatment_index = SecureRandom.random_number(1..no_reps)
end
end
Try to #shuffle prepopulated array:
#trial.repetitions.in_groups_of(no_reps).each_with_index do |a, i|
treatment_indexes = (1..no_reps).to_a.shuffle
a.each_with_index do |r, j|
r.repetition_index = i + 1
r.treatment_index = treatment_indexes[j]
end
end
UPD: If you take care about speed:
treatment_indexes = (1..no_reps).to_a
#trial.repetitions.in_groups_of(no_reps).each_with_index do |a, i|
treatment_indexes.shuffle!
...
I am working on a kind of order where I have multiple amount in different currencies in just one attribute. So am trying to make sum on different currencies inside that attribute using other attributes in the table, which works fine but outputs the result as a count of all the rows instead of just showing the sum of the random values calculated.
orders_controller.rb
module Admin
module Statistic
class OrdersController < BaseController
def show
#orders_grid = ::Statistic::OrdersGrid.new(params[:statistic_orders_grid]) do |value|
value.page(params[:page]).per(20)
end
#assets = #orders_grid.assets
##fee_groups = {:fee => #assets.sum(:fee)}
#fee_groups = {
:fee => #assets.sum{|t|
olaoa = t.type
market_string = t.currency
base_currency = market_string.slice(0..2)
quote_currency = market_string.slice(3..5)
if olaoa == 'OrderBid' and base_currency == 'btc'
"#{ t.fee.to_s + ' ' + base_currency.upcase }"
elsif olaoa == 'OrderAsk' and quote_currency == 'ngn'
"#{ t.fee.to_s + ' ' + quote_currency.upcase }"
end
}
}
#orders_filter = true
#orders_group = true
end
end
end
end
summary.htm.slim
.panel.panel-default
.panel-heading
h4.panel-title.row
a data-parent="#filter-accordion" data-toggle="collapse" href="#summary"
span.col-xs-8.text-muted = t('admin.statistic.summary')
span.col-xs-4.text-right.text-muted = t('admin.statistic.click-to-expand')
#summary.panel-collapse.collapse
.panel-body
.datagrid-groups
- if !#orders_group
- if groups
- groups.each do |key, val|
.datagrid.group.row
span.col-xs-2.title = t("admin.statistic.#{controller_name}.#{controller.action_name}.#{key}")
span.col-xs-10.value = val
- if #orders_group
/ Summary Count Loop
- if groups
- groups.each do |key, val|
.datagrid.group.row
span.col-xs-2.title = t("admin.statistic.#{controller_name}.#{controller.action_name}.#{key}")
span.col-xs-10.value = pluralize(val, 'Order')
/ Summary Fees Loop. This is the Fee loop causing problem if am rigth and I dont know how to fix this.
- if #fee_groups
- #fee_groups.each do |key, val|
.datagrid.group.row
span.col-xs-2.title = t("admin.statistic.#{controller_name}.#{controller.action_name}.#{key}")
span.col-xs-10.value = val
The result of the code
So as you can see it renders 0.0BTC 5 times because the filter only has 5 orders. How do i deal with this. I want just the sum of all BTCs to show in the result instead of showing it 5 times.
Any help will be appreciated.
Because you sum strings in you're #fee_groups query that will results in putting strings next to each other instead of a total amount.
If you call it like this
#fee_groups = { fee: #assets.sum{|t| t.fee}}
You will get the total sum of you're assets.
Let's say I have a loop repeating 1000 times.
Previous to the loop, I set 1000 variables, like so:
#n1 = "blabla"
#n2 = "blabla"
#n3 = "blabla"
#n4 = "blabla"
...
I also have a variable #count that counts which iteration the loop is on, ie. it starts at 1 and increases by 1 with each loop. What I want to do is print #n1 if #count = 1, print #n2 if #count = 2, and so forth. In other words, I want ruby to use the value of #count to decide which #n_ variable to use. I don't want to use conditional statements, because I'd need 1000 of them.
Something like this:
#count = 1
if #count < 1001
puts #("n + #count")
#count = #count + 1
end
Is there a way to do this?
Let's say you have an instance called foo, with a thousand instance variables, to loop through them all you could do:
foo.instance_variables.each do |v|
p foo.instance_variable_get(v)
end
That said, you can also use the string name to fetch them:
1000.times do |count|
p foo.instance_variable_get("#n#{count}")
end
Yes, you can do do this:
if #count < 1001
instance_variable_set("##{#count}", #count + 1)
end
It would be more idiomatic to store in a hash, e.g.
h = {}
if #count < 1001
h[#count] = #count + 1
end
While you can use something like instance_variable_get, you would usually use an array or an hash to store your strings:
n = ["blabla", "blabla", "blabla", ... ]
count = 0
if count < 1000
puts n[count]
count += 1
end
In my Rails 3.2 app a Connector has_many Incidents.
To get all incidents of a certain connector I can do this:
(In console)
c = Connector.find(1) # c.class is Connector(id: integer, name: string, ...
i = c.incidents.all # all good, lists incidents of c
But how can I get all incidents of many connectors?
c = Connector.find(1,2) # works fine, but c.class is Array
i = c.incidents.all #=> NoMethodError: undefined method `incidents' for #<Array:0x4cc15e0>
Should be easy! But I don't get it!
Here’s the complete code in my statistics_controller.rb
class StatisticsController < ApplicationController
def index
#connectors = Connector.scoped
if params['connector_tokens']
logger.debug "Following tokens are given: #{params['connector_tokens']}"
#connectors = #connectors.find_all_by_name(params[:connector_tokens].split(','))
end
#start_at = params[:start_at] || 4.weeks.ago.beginning_of_week
#end_at = params[:end_at] || Time.now
##time_line_data = Incident.time_line_data( #start_at, #end_at, 10) #=> That works, but doesn’t limit the result to given connectors
#time_line_data = #connectors.incidents.time_line_data( #start_at, #end_at, 10) #=> undefined method `incidents' for #<ActiveRecord::Relation:0x3f643c8>
respond_to do |format|
format.html # index.html.haml
end
end
end
Edit with reference to first 3 answers below:
Great! With code below I get an array with all incidents of given connectors.
c = Connector.find(1,2)
i = c.map(&:incidents.all).flatten
But idealy I'd like to get an Active Records object instead of the array, because I'd like to call where() on it as you can see in methode time_line_data below.
I could reach my goal with the array, but I would need to change the whole strategy...
This is my time_line_data() in Incidents Model models/incidents.rb
def self.time_line_data(start_at = 8.weeks.ago, end_at = Time.now, lim = 10)
total = {}
rickshaw = []
arr = []
inc = where(created_at: start_at.to_time.beginning_of_day..end_at.to_time.end_of_day)
# create a hash, number of incidents per day, with day as key
inc.each do |i|
if total[i.created_at.to_date].to_i > 0
total[i.created_at.to_date] += 1
else
total[i.created_at.to_date] = 1
end
end
# create a hash with all days in given timeframe, number of incidents per day, date as key and 0 as value if no incident is in database for this day
(start_at.to_date..end_at.to_date).each do |date|
js_timestamp = date.to_time.to_i
if total[date].to_i > 0
arr.push([js_timestamp, total[date]])
rickshaw.push({x: js_timestamp, y: total[date]})
else
arr.push([js_timestamp, 0])
rickshaw.push({x: js_timestamp, y: 0})
end
end
{ :start_at => start_at,
:end_at => end_at,
:series => rickshaw #arr
}
end
As you only seem to be interested in the time line data you can further expand the map examples given before e.g.:
#time_line_data = #connectors.map do |connector|
connector.incidents.map do |incident|
incident.time_line_data(#start_at, #end_at, 10)
end
end
This will map/collect all the return values of the time_line_data method call on all the incidents in the collection of connectors.
Ref:- map
c = Connector.find(1,2)
i = c.map(&:incidents.all).flatten
I want to make a loop on a variable that can be altered inside of the loop.
first_var.sort.each do |first_id, first_value|
second_var.sort.each do |second_id, second_value_value|
difference = first_value - second_value
if difference >= 0
second_var.delete(second_id)
else
second_var[second_id] += first_value
if second_var[second_id] == 0
second_var.delete(second_id)
end
first_var.delete(first_id)
end
end
end
The idea behind this code is that I want to use it for calculating how much money a certain user is going to give some other user. Both of the variables contain hashes. The first_var is containing the users that will get money, and the second_var is containing the users that are going to pay. The loop is supposed to "fill up" a user that should get money, and when a user gets full, or a user is out of money, to just take it out of the loop, and continue filling up the rest of the users.
How do I do this, because this doesn't work?
Okay. What it looks like you have is two hashes, hence the "id, value" split.
If you are looping through arrays and you want to use the index of the array, you would want to use Array.each_index.
If you are looping through an Array of objects, and 'id' and 'value' are attributes, you only need to call some arbitrary block variable, not two.
Lets assume these are two hashes, H1 and H2, of equal length, with common keys. You want to do the following: if H1[key]value is > than H2[key]:value, remove key from H2, else, sum H1:value to H2:value and put the result in H2[key].
H1.each_key do |k|
if H1[k] > H2[k] then
H2.delete(k)
else
H2[k] = H2[k]+H1[k]
end
end
Assume you are looping through two arrays, and you want to sort them by value, and then if the value in A1[x] is greater than the value in A2[x], remove A2[x]. Else, sum A1[x] with A2[x].
b = a2.sort
a1.sort.each_index do |k|
if a1[k] > b[k]
b[k] = nil
else
b[k] = a1[k] + b[k]
end
end
a2 = b.compact
Based on the new info: you have a hash for payees and a hash for payers. Lets call them ees and ers just for convenience. The difficult part of this is that as you modify the ers hash, you might confuse the loop. One way to do this--poorly--is as follows.
e_keys = ees.keys
r_keys = ers.keys
e = 0
r = 0
until e == e_keys.length or r == r_keys.length
ees[e_keys[e]] = ees[e_keys[e]] + ers[r_keys[r]]
x = max_value - ees[e_keys[e]]
ers[r_keys[r]] = x >= 0 ? 0 : x.abs
ees[e_keys[e]] = [ees[e_keys[e]], max_value].min
if ers[r_keys[r]] == 0 then r+= 1 end
if ees[e_keys[e]] == max_value then e+=1 end
end
The reason I say that this is not a great solution is that I think there is a more "ruby" way to do this, but I'm not sure what it is. This does avoid any problems that modifying the hash you are iterating through might cause, however.
Do you mean?
some_value = 5
arrarr = [[],[1,2,5],[5,3],[2,5,7],[5,6,2,5]]
arrarr.each do |a|
a.delete(some_value)
end
arrarr now has the value [[], [1, 2], [3], [2, 7], [6, 2]]
I think you can sort of alter a variable inside such a loop but I would highly recommend against it. I'm guessing it's undefined behaviour.
here is what happened when I tried it
a.each do |x|
p x
a = []
end
prints
1
2
3
4
5
and a is [] at the end
while
a.each do |x|
p x
a = []
end
prints nothing
and a is [] at the end
If you can I'd try using
each/map/filter/select.ect. otherwise make a new array and looping through list a normally.
Or loop over numbers from x to y
1.upto(5).each do |n|
do_stuff_with(arr[n])
end
Assuming:
some_var = [1,2,3,4]
delete_if sounds like a viable candidate for this:
some_var.delete_if { |a| a == 1 }
p some_var
=> [2,3,4]