Quotes About Variables

To preserve state consistency, update related state variables in a single atomic operation.

Every shared, mutable variable should be guarded by exactly one lock. Make it clear to maintainers which lock that is.

book variables, student variables, and school variables.

Occam's razor: The simplest explanation that accommodates all variables is most likely the truth.

In the words of the systems thinker John Sterman, 'The most important assumptions of a model are not in the equations, but what's not in them; not in the documentation, but unstated; not in the variables on the computer screen, but in the blank spaces around them'.

problems of organised complexity, which involve a sizeable number of variables that are 'interrelated in an organic whole' to create a complex but organised system.

Locking is not just about mutual exclusion; it is also about memory visibility. To ensure that all threads see the most up-to-date values of shared mutable variables, the reading and writing threads must synchronize on a common lock.

However, we do not recommend relying too heavily on volatile variables for visibility; code that relies on volatile variables for visibility of arbitrary state is more fragile and harder to understand than code that uses locking.

You can use volatile variables only when all the following criteria are met: Writes to the variable do not depend on its current value, or you can ensure that only a single thread ever updates the value; The variable does not participate in invariants with other state variables; and Locking is not required for any other reason while the variable is being accessed.

A special case of thread confinement applies to volatile variables. It is safe to perform read-modify-write operations on shared volatile variables as long as you ensure that the volatile variable is only written from a single thread. In this case, you are confining the modification to a single thread to prevent race conditions, and the visibility guarantees for volatile variables ensure that other threads see the most up-to-date value. Because

If multiple threads access the same mutable state variable without appropriate synchronization, your program is broken. There are three ways to fix it: Don't share the state variable across threads; Make the state variable immutable; or Use synchronization whenever accessing the state variable.

All variables are independent.

Nem sempre há segurança nos números, e às vezes as circunstâncias influem muitas nas ações dos homens.

If happiness is dependent on outside variables, it can't last. Variables always change. Real happiness has to come from within.

In Operations, many of our data sets have what we call 'chi squared' distribution. Using

It is in adolescence that most of us grasp that life--our own life--is a problem to be solved, that a set of personal unknowns must now be factored together with the frightening variables of experience. The future suddenly appears--it is the space upon which the answers will be inscribed.

Our brain is not cut out for nonlinearities. People think that if, say, two variables are causally linked, then a steady input in one variable should always yield a result in the other one. Our emotional apparatus is designed for linear causality. For

while the bulk of their risks came from outside their models.

Modernity provides too many variables (but too little data per variable), and the spurious relationships grow much, much faster than real information, as noise is convex and information is concave. Increasingly, data can only truly deliver via negativa–style knowledge—it can be effectively used to debunk, not confirm.

We can see that my activity in the market (and other random variables) depends far less on where I think the market or the random variable is going so much as it does on the degree of error I allow around such a confidence level.

Regression analysis enables us to go one step further and "fit a line" that best describes a linear relationship between the two variables.

these cases, the goal is to find two groups of subjects who are broadly similar except for the application of whatever "treatment" we care about.

The entropy of the world in the far past appears very low to us. But this might not reflect the exact state of the world: it might regard the subset of the world' s variables with which we, as physical systems, have interacted. It is with respect to the dramatic blurring produced by our interactions with the world, caused by the small set of macroscopic variables in terms of which we describe the world, that the entropy of the universe was low.

We observe the universe from within it, interacting with a minuscule portion of the innumerable variables of the cosmos. What we see is a blurred image. This blurring suggests that the dynamic of the universe with which we interact is governed by entropy, which measures the amount of blurring. It measures something that relates to us more than to the cosmos.