When we write vectors as matrices, we tend to write an $n$-dimensional vector vector as $n \times 1$ column matrix. We emphasize that the gradient vector is defined only for scalar-valued functions. For vector valued functions, we will stick with viewing the derivative as a matrix.
Gloomy Addiction Relapse Statistics. Drug and alcohol rehab statistics show that the percentage of people who will relapse after a period recovery ranges from 50% to 90%. This is a frightening statistic and it is often used as justification for those who wish to carry on with their addiction.
1 That is, they went into rehab because of marijuana and its effects on their bodies and minds. 2  Twenty-eight percent of those admissions or 103,000 people were between twelve and seventeen years old. ( 3 This figure applies only to publicly-funded facilities so the actual number is much higher.).