Advanced Fortran Programming : 021 : Derived Data Types Video Lecture | Introduction to Fortran Programming (AdvancedLevel) - Database Management

hello guys my name is Aaron and welcome
to my channel this series is a series of
tutorials and advanced Fortran
programming now in this tutorial he'll
be looking at one interesting concept
and with a concept that will be very
very used and very very important for
you know data handling and data handling
and for grouping data and processing
them as one unit okay this kind of debt
this is this unit is actually common
this type is actually mean what are you
going to do today is that we will be
looking at one important concept called
us derived data types
now these derived data types are exactly
more or less similar to the structures
the structures in C and C++ okay now
what is a delayed data type is that it
is kind of similar to arrays but the
same time is kind of similar to
available Erin Merryn if you're defining
a new kind of data type where an H the H
Jared at each derived data this actually
a composite collection of multiple basic
data types see in your in Fortran okay
the basic fundamental data types are
integers integers real numbers logical
logical number logicals
complex numbers and so on okay
but even characters so on but if you
want to make a composite composite
collection of these okay and if you
compose a collection of these is a
little difficult if you want to collect
have a homogenous collection of these
values like an integers characters and
real numbers and logic numbers and all
you have the arrays okay and you have
the erase okay but if you want to color
if you want to combine an integer a
float a character and several others
together as a single variable and they
operate all of these values separately
inside then photon does not have any
feature as a to define a heterogenous
variable like that but that kind of a
feature can be implemented it can be
that kind of feature can be implemented
nicely using this type variable using
this type definition or did they were
using their data types okay
now enough of me talking of that I like
I'll walk you guys through okay what see
look at this line over here okay
I'm using I'm using this keyword type to
define a kind at the name of Adlai data
type now this data data type is called a
stud okay and inside this data data type
I am able to Inc incorporate two
variables inside and each of them are
different see them are different in
nature one is an integer names ID and a
score n another data type is actually a
character array of 20 20 units longer
okay now in a normal array or a normal
for an if you were to combine these two
to form a single entity in the form of
an array it's not it's not possible but
using this type attribute over here we
are we can photon allows you to define
define a new way a new data type okay
big new data type well and you can
combine and merge integers and
characters here not only integers in
catters you can also include real
numbers complex numbers logical numbers
even even erase even integer erase
complex are as logical is what not even
even if even you can clone combine those
and operate them as a separate entity
know where where does this kind of
arrangement is used I'll give an example
suppose we have suppose in the class of
say 50 people okay
they're like 60 students in a class and
now each student has a sudden add a
certain various I don't data to data
with like his name yeah to start with
this name then he might have a roll
number or and some kind of an identity
number okay then he might then maybe his
age may be a sex maybe he may be a boy
or a girl that that that that that
gender distant that then a deposition
variable the mark sealed might have
scored in four to four or five subjects
let's see waters yeah
his average the class average in the
class is rank and all so if you guys
notice for each and every student you
have like seven you can you can put like
seven or eight variables for each and
every student now there are fifty
students I never like eight variables
for each student they've like 400 odd
variables to define and if they fine and
make now one that'd be hard okay but if
this if you define that in this kind of
us this nice type we kind of define this
in tight variable like this that
definition becomes just quite immensely
easy okay
all I ever do is just define a type two
for a particular student particular
student say just I'm just including two
things over here like an iodine ID this
is ID number and then and then this name
simple as that okay
and if you guys want you can include the
other subject names other some other
subjects is gender like male or female
as age if you want like watch this
average watch this rank and the clot is
what this or her rank in the class so on
and so for you can just add so many
variables now because of this kind of
feature kind of feature you're safe
you're like you're defining eight
variables eight or seven variables under
one under one type definition and you
can use that type definition to define
as many students as you want and without
loosing it without having having the
tiresome or cumbersome need to repeat it
repeat it again and they replace the
variable generation again and again and
again okay now this is how the type goes
now if you want to access okay I'll come
to the access point later now what I did
is that I defined some character arrays
namely prof underscore name one start
underscore name and this is where a
process is a professor named this is a
student name okay like there are defined
three professor names and three student
names and if similarly I'm using
integers are defined
three professor IDs and three student
IDs okay know how with this type being
defined like this with this type being
defined like this I can create multiple
student names like miles like this now
this is the type this stud is actually
the derivative type for the student okay
and you say if I'm about to create a new
variable for if I were to set if I were
to create a certain separated separate
the set of data for say one student all
I can do is that I just have to type
right type within brackets stud and
define a variable called a stud one now
this third one is actually derived
variable they write variable havin it
with which has the ID number and name
one to it now if that if I wanted to
define the attribute I did number ID
number or name for another student let's
say all I have to do is that I just have
to type three simple as that now stat3
will have will hold the variables will
hold the values for another student
suppose if you want this to be defined
like an array let's say array let's say
all I do is that I give the type you
write the type over here type stud and
then to give it as an array simple as
that now if this if this array now this
is actually have two value okay suppose
if I were to that is 50 okay now they
start to is a single variable okay and
each of its 50 variables will be a
charge 50 variables will have will have
a it will be a derived very will be a
will be a variable of type stud and
inside those 50 each of those stud
variables listed variables have two of
these variables integer ID number and
name name so if you guys notice they've
this way this way it's absolutely easy
to absolutely easy to monitor the
monitor the monitor or collect or assign
or use the parameter user
data for each and every student is an
every student and in a class is in this
way now order define decide let's define
this to be to simpler for simple cell
for simplicity and here I just setting
the number of variables here to be just
two okay now we look at an example now
okay you ignore this professor ignore
this professor type for now okay we will
come to the we'll come to that later
okay now what I did what I have done
here is that okay
he is like this now this student this
started this way derived variable start
one has two variables in it idea and
only idea in the squad number idea in
the score now you know which is the ID
number and the name okay and if I want
to access that and he want to use them
you use it to manipulate or use it just
like an other variable what I have to do
is I just have to type like this I have
to use the percentage sign to get the
variable get the value so what I have to
do is that I just have to type the delay
data type name put a percentage sign and
say the variable inside this Lehrer data
type okay so if you ever had to write
like this stud one stud one percentage
ID underscore now you know what does it
mean is that various we are accessing
the variable ID underscored enum idea
idii ID number variable ID number in
this there a data type stud1 okay and
we're accessing that and we're putting
this to be equal to stutter I started a
square I D 1 so what happens is that
this ID value will this ID value inside
this data type stud1 will be set to 31
similarly okay if this is if this if the
start very variable is they actually
defined if this data data type is
defined I can array okay I can set E I
can access the variable value for each
and every stud verse and very like this
now start to of one access accesses the
first element first start type divided
divided element in dimension to first
start the type the red type in this
start to and I since science its
Aidid number two stud underscore ID to
start on the square d 2 is over here and
this will assign the second this
statement over here because of this 2
over here will decide I will assign a
second value will call the second stud
there a data type in this stud to array
start to come type array okay and in
that it'll set the ID value ID number to
be the value stud on a square ID 3 okay
similarly similarly I can set the name
of assets at the name of the
corresponding stud stud vanish over here
using this using this statement over
here suppose if I want to use them use
them somewhere for some manipulation
undergo some calculation I can just
instead of this single variable over
here I can just use this now this way if
you want to access variable if you want
access loops or something of the loose
or if you want access access do some
nested loops or something of that sort
this kind of star definitely this kind
of delay data type definition is very
very useful and if you and I what I'm
doing here is that I'm printing the
student name of a student names student
IDs over here and I'm printing the
student names over here okay now that
being said now let's look at look at
this hope you guys are okay before I go
on to the next one
hope you guys understood all understood
up to here okay now let's go on to the
the second part of it second part of
this thing
DeRay datatype tutorial suppose if I
have suppose if you want to pass this
type they read data type to some other
function or a subroutine let's say then
it's little then it's not that easy if I
define this a value define this type
within a func within a program like this
then all the procedures like the
function subroutines that are defined
okay within the program they can access
it now
access it easily but if you want this
there at the if you want this kind of de
redditor to be available to other
translation subroutines okay then
there's only one simple way to do that
and that is using the modules now what I
have here is that I just have a module
module called as dairy okay it starts
here and ends here and inside this
inside this I use this implicit nun and
it is the same command okay
to define a tie I define a new derive
data type called as prof. this by
intuition you guys might have figured
that this will store the professor's ID
ID number and the professor's name
suppose in the same if suppose you have
a college or a school or any play higher
education place or even the Services
Institute let's say and they have a lot
of professors in the process working
over there if you wanna store the I in
ID number identity number ID number and
their name or something of that sort
this professor this prof type can be
used over there okay I'm just limiting
to the various to be now to be too but
you can if you want you can add so many
other variables of your choice it is
just up its left up to you now because I
put this I define this type of professor
type professor to the power here and I
use the same keyword to to make it
available to make this type available to
everybody I do I make this type
available to everybody now what I have
to do is that if you want to use this
professor they're a data type enough my
my function I'm a prop in my program all
I reduced they said I don't I have to
use this module inside my program and if
I use this this data type prof is will
be available now since this is available
here in my program I can define I can
define a prof one derived variable base
of type prof okay and using the same I
define I define a 2d define an array a
one-dimensional array of the prof to
prepare the dead types okay just like
how we did
for the student okay like that I can do
that and I just like just like the
student I can assign it's about I saying
the ID numbers using the values over
here and the names just like using or
using the values over here just like how
we did for student and to print all this
okay I'm not using I mean since we saw
this working over here okay
I thought either a little better to give
you guys an example of how to get this
with jobs printed in in the subroutine
okay so what I do is I just call the
subroutine there I our dairy underscore
print and this dairy underscore print is
nothing but it's nothing it just prints
these six statements with respect to the
professor and that's it and what this
does is that is this again uses this
dairy this their this module over here
now if I were to comment this out he may
just had to pass this okay compile this
it'll throw another okay so this way if
you guys notice it is not possible to
pass the derive data type directly into
a function or a subroutine because the
functions and subroutines they know by
default that they are they by default
that they can handle normal data types
like real complex real integer complex
and those okay but they do not know both
functions are both functional
subroutines they do not know how to
handle the right hundred their data
types for if you want them to if you
want them to know as to how to handle it
then there is only this is this is only
possibility you have to go with for go
for modules and uses the same command
suppose if ever to come on the same
command and run this compiled and run
this sometimes they will work no no they
will work they will work okay but the
same command is used to have set some
default values if you want to set some
default values okay now what I do is
that I just passed this value to be one
this value to be two and if I pass this
value to be professor x
okay professor professor Eck's okay
now if ever to save this okay
compile build and run this you don't see
any change over here you don't see any
change over here because of because the
way this program is written these values
get modified okay now what I do is that
I call the statement again I call this
statement after the definition after
this definition if I were to compile
build and run this
you guys notice when I call this they
call these values initially okay they
already have values certain set said to
them too and Professor X so when this
data when this subroutine call has been
made it prints it prints the student ID
to Professor ID to be 2 and the proper
you know the forget of other forget
about this I saw is just a typo i instr
I should have changed this reproof one
profitable but anyway that doesn't
matter
modern matters here is the values over
here okay
it just said that sets the values to be
two since the values should be two and
Professor X just like what you mentioned
over here so then in this way okay even
if you are there are data types do not
have a value you can use the same
command to have fix a default value to
them so that you can access them later
you can access them later and if you use
you can access them later and the
suppose if you had to reassign some
values like them values like these like
how we did did over here those valleys
get over those valleys get overwritten
so nothing to worry about okay that's so
that's the reason why yeah even without
any values beings defined over but if I
had to I mean this is the this because
this is the reason why even without any
values being defined over saved defined
over here on the top just if I just
declaring a but not assigning any okay
this this function prints the value
nicely but if I were to remove the save
function
sorry okay if I were to remove the save
function if I were to compile
than run this passionately it works
passionately it works sometimes they
some and sometimes they may not work in
some compilers fascinating my compiler
is kind of working
I have no absolutely no idea as to how
this works okay let me remove the star
dot o star dot exe okay and derived okay
and let me move this star dot mod file
over here
okay started model file over here they
were to compile if I were to compile
this and run this and I remove the same
comment over here okay okay
I remove the same comment over here they
were to compile this in one shot compile
and build is in one shot using this
command sorry I think this should be
sigh I forgot i what am i typing g42 and
star dot F F 95 okay I get it I will get
this finally a dot out if I were to
compare this here dot o UT o UT
surprising it prints maybe in some
compilers do if you don't put the same
command and this type does the error
that may not be available okay but this
is the thing but this is the thing you
put the save command okay if you were to
change this data type value in somewhere
and read change this data type the
inbuilt data type of this type prof in
some other function of some other
subroutine the inbuilt data type value
some of those functions are more
subroutine then that gets that gets you
know reflected in all the programs and
all the subroutines which uses this data
type so that's the reason why save issue
sometimes even if you don't even it is
not at all required but it's kind of
required if you especially if you have a
values like this and if you want to make
changes to the basic data type itself to
everybody everywhere else okay now this
kind of thing will be used can be used
in several places especially for data
handling and stuff data handling and if
you want to work if you want to work
with the data structures kind of pasta a
dagger such as kind of job you're
working with that kind of a job or if
you have that kind of a process or what
to do and if they have that kind of
number crunching stuff for data hammocks
have to do ok
this delayed deny data types will be
very very useful on that regard all
right hope this hope you guys understood
this example I made my I did my best to
explain this in explain this explain
this okay you guys know does this has a
lot of advantages features advantages
peaches and which can be considered
which can be used quite nicely for
several applications so
it all you need is just a proper
application and if you have a proper
application you guys can do a lot of
stuff over here a lot of stuff using
these ok thank you guys for watching and
I'll see you guys next tutorial take
care bye